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Journal Cover Australian Journal of Water Resources
   [7 followers]  Follow    
   Full-text available via subscription Subscription journal
     ISSN (Print) 1324-1583
     Published by RMIT Publishing Homepage  [419 journals]   [SJR: 0.489]   [H-I: 3]
  • Volume 17 Issue 2 - Below the double bottom line: The challenge of
           socially sustainable urban water strategies
    • Abstract: Sofoulis, Z Recent interview-based research on how Australian urban water professionals grasp the social aspects of sustainable water management suggests that interest in these dimensions outstrips understanding of them, and that more culturally intelligent, socially realistic and ethically sensitive notions of people, culture and society are needed. Despite lip-service to 'triple bottom line' assessments of policies and developments, Australia's policymakers have advanced no further than a 'double bottom line' based on economic and environmental values, the latter preferably expressed in dollar terms. The economic (or market relation) also substitutes for the social dimension in a continued policy emphasis on customers rather than citizens or community members. An overemphasis on behavioural economics, a lack of social, political and cultural theory, and neglect of people's actual practices means that much policy and research around water fails to grapple with such basic social elements as gender, different roles and access to resources within households, cultural diversity, or ethical orientations. A major challenge is to mobilise rather than ignore the altruistic and socially-oriented human capacities for adapting to change beyond the customer relation or the confines of technical and economic rationality; including by collective innovations in values and practices of caring for water.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Systematic causal inference and knowledge transfer
           between science and policy: Eco Evidence in water management
    • Abstract: Skinner, DS; Webb, JA; Nichols, SJ; Stewardson, MJ Effectively transferring complex scientific ideas into the policy domain is a serious challenge, but an essential one given the important role of science in assessing the implications of a changing climate and resulting water shortages in Australia. Eco Evidence, a method for conducting systematic reviews of the scientific literature using causal criteria analysis, was developed for the eWater Cooperative Research Centre to help bridge this gap between science and policy. It provides a transparent and repeatable method for assessing the strength of the available scientific evidence regarding particular management actions. However, if evidence is used to justify decisions rather than to provide options and likely outcomes of these options to stakeholders, its effectiveness can be undermined. By drawing on interdisciplinary theories of uncertainty in the science-policy arena, this paper demonstrates how Eco Evidence can be used in evidence-based practice in a manner that does not interfere with the effective participation of a range of stakeholders in the decision-making process.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Understanding the vulnerability, resilience and
           adaptive capacity of households in rural Victorian towns in the context of
           long-term water insecurity
    • Abstract: Stebbing, MS; Carey, M; Sinclair, M; Sim, M While the range of impacts of a changing climate on farming communities has been extensively studied in Australia, little is known about how individuals and households in small rural towns adapt to the effects of long-term water insecurity. The health and wellbeing impacts of climate variability may be experienced as direct or indirect health impacts or as reduced access to health and other services as reduced economic viability affects rural towns. Identifying risk factors for vulnerability and local measures and practices that will reduce health and wellbeing impacts offers evidence for climate change adaptation policy direction at the local, state and national level. This paper discusses the results of a study that aimed to improve understanding of the vulnerability, resilience and adaptive capacity of rural communities at the household scale. Focus groups with town residents and key informant interviews were conducted in three rural towns in Western Victoria experiencing differing water security challenges during a period of 'drought'. Perceived health and wellbeing impacts and the differing ways in which residents adapted their lives to accommodate these changes were explored. The study revealed a range of physical, mental, oral health and food security impacts on health and wellbeing. There were clear gender differences in the ways that men and women identified, communicated and dealt with these impacts. Perceived water quality and cost were shown to be key determinants of acceptance of the small town reticulated water supply. The results of this study suggest that a history of conservatism, degree of community connectedness and communication, the small town ethic of self-reliance, and the openness of government to community involvement in decision making, planning and action around water supplies are important factors in determining resilience to threats to water security in small rural towns.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Climate change adaptation of urban water management
           systems in the wet/dry tropics
    • Abstract: Saunders, NJ; Peirson, WL Climate change impacts in the wet/dry tropics are expected to include an increase in extreme daily rainfall events, mean evaporation rates and mean temperatures. The proposed Weddell development, located 40 km south of Darwin, is forecast to have up to 10,500 residents by 2021. This increasing population coupled with projected climate change impacts will increase demand for potable water and exacerbate existing problems associated with the region's wastewater treatment infrastructure. Water sensitive urban design (WSUD) provides an effective method of improving discharge water quality, providing water storage capacity and achieving peak fl ow attenuation. Using the Weddell development as a point of reference this study has shown that WSUD designs implemented in sub-tropical and temperate areas are not directly transposable to the wet/dry tropics. WSUD designs need to be adapted to cope with the extended dry period characteristic of the wet/dry tropics. While WSUD elements could constitute effective adaptation measures in the wet/dry tropics, there is a definite need for long-term studies that assess the practicality of maintaining functioning WSUD elements in the region. In this contribution we discuss the key issues associated with WSUD in the Northern Territory and the outcomes of a consultation workshop with government agencies.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Energy sector transformation: Implications for water
           governance
    • Abstract: Hussey, K; Carter, N; Reinhardt, W The energy sector is undergoing major transformation. An under-recognised aspect of this transformation is the implications it has for the availability and quality of our freshwater water resources. Indeed, population growth combined with climate change and associated policies to address it, pose significant challenges for how we use our precious water resources, and the energy sector is set to become an increasingly important 'user' of water in the decades to come. However, despite the important links, and parallels, between the two sectors, the two commodities are perceived, governed and managed in markedly different ways. This paper explores four aspects of the energy sector's transformation that pose particular challenges for water governance.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Climate change adaptation in the Murray-Darling Basin:
           Reducing resilience of wetlands with engineering
    • Abstract: Pittock, J; Finlayson, C M Conflict over water allocations and the need to adapt to climate change in Australia's Murray-Darling Basin has resulted in decision makers choosing engineering interventions to use water more efficiently for wetlands conservation. We review a range of policy and infrastructure adaptation measures implemented in the Basin by governments. The water supply and demand 'environmental works and measures' adopted in the Coorong and Lower Lakes region, as well as along the River Murray, are assessed and compared with the opportunity costs for ecosystem-based adaptation. The results suggest that risks of disruption to ecological processes, desiccation of wetland areas and institutional failure with infrastructure-led adaptation measures are little appreciated. Further, ecosystem-based measures to maintain a more diverse range of ecological processes that would spread risk and conserve a more diverse range of biota have not been identified or adopted by governments. We conclude that as a primary adaptation to climate change environmental works and measures may represent overly-narrow or mal-adaptation that can reduce the resilience of wetland ecosystems.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Disposable infrastructure including relocatable
           buildings: Adapting to climate change
    • Abstract: Gordon, AD In Australia most coastal villages, towns and suburbs started as camping areas, fishing shacks and/or holiday houses, all with basic, self-contained infrastructure. As the intensity of development increased, so did the demand for more conventional 'permanent' infrastructure. The assumption behind this evolution was that the properties the infrastructure was servicing were going to exist for a long time into the future. Shoreline recession due to sediment imbalances, but more recently also associated with the likely impacts of climate change, places permanent styled coastal development and infrastructure at risk. The problem of managing such a situation is exacerbated by the still poorly defined climate future and hence the uncertainty as to when the infrastructure, and the development it serves, will be impacted. Given this uncertainty, a novel way of approaching the problem is to accept the potentially temporary nature of the real estate and hence adopt an adaptive philosophy of disposable infrastructure and relocatable buildings. The challenge is to provide an acceptable standard of building and infrastructure in areas that may come under threat in the future, and to facilitate the implementation of progressive withdrawal as shoreline recession occurs. This calls for an innovative approach to infrastructure and building design.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Drought severity estimation under a changing climate
    • Abstract: Tan, KS; Rhodes, BG This paper describes an approach to estimate drought severity for drought response planning and urban water management considering the impacts of climate change and variability. Low fl ow frequency analysis was used to estimate drought severity (eg. 1-in-100-year average recurrence interval) of different drought durations from several months to years. Traditionally this was done using available historical streamflow record. However, recent research including the South Eastern Australian Climate Initiative has indicated that the prolonged drought experienced in southeastern Australia including Melbourne in the recent decade since 1997 has been unprecedented in historical context, and is potentially part of a long-term trend associated with global warming. This raises the issue of the practicality of the assumption of hydrologic stationarity. To account for the potential for more severe and frequent drought events, an adaptive approach is needed to adapt to the drier future in a changing and variable climate by considering experience from the recent 1997-2009 drought and the latest climate change projections. In this paper, drought severity for the Melbourne system is estimated based on historical streamflow data with monthly fl ow prior to 1997 adjusted using a fl ow duration curve decile method to reflect the recent dry conditions of 1997-2009. The approach is consistent with recommendations in the Victorian Guidelines for the Development of a Water Supply-Demand Strategy (DSE, 2011). The results indicate that drought severity and frequency increased by an order of magnitude under a changed climate based on a 'return to dry' scenario. This shift in severity and frequency highlights the need for adaptive planning methods to address changes in hydrologic conditions under a variable and changing climate. However, it also raises many challenges for drought planning including uncertainties in climate change projections, attribution of recent drought to climate change and variability, and the appropriate hydro-climate baseline for applying climate change projections.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Provision of usable projections of future water
           availability for southeastern Australia: The South Eastern Australian
           Climate Initiative
    • Abstract: Post, DA; Moran, RJ Projections of future water availability are required by water managers and policy makers in order to take action to mitigate some of the potentially negative impacts of climate change on water supplies in the urban, agricultural and environmental sectors. However, in order to do this, these projections must have some level of confi dence associated with them, and even if this is the case, the research community must make the data and/or information available in a format that is directly usable by water managers and policy makers. This paper presents results from a water availability study recently carried out across southeastern Australia as part of the South Eastern Australian Climate Initiative. More importantly, it shows how the results of this study have been used in defi ning a range of plausible future streamfl ow scenarios to be used by water resource managers in the state of Victoria in updating its water supply-demand strategies for the next 50 years. Climate change projections for this region were summarised by creating 'dry', 'wet' and 'median' future runoff scenarios for 2030 and 2060 based on the second driest, second wettest and median global climate model (GCM) results. These results were then averaged across 27 catchments covering the state of Victoria. We contend that in areas such as the state of Victoria where there is near-unanimous agreement among GCMs as to the direction of climate change impacts on rainfall, along with theoretical understanding consistent with changes in large scale circulation in a warmer world, projected changes in water availability can be used by water resource planners to assist them in better planning for future changes in supply.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - The importance of understanding drivers of
           hydroclimatic variability for robust flood risk planning in the coastal
           zone
    • Abstract: Kiem, AS; Verdon-Kidd, DC Previous work has established that the risk of climate related emergencies (eg. floods, droughts, bushfires, etc.) in Australia, and many other parts of the world, is non-stationary. That is, the chance of an extreme climatic event occurring is not the same from one year to the next and is in fact dependent on the state of the various ocean-atmospheric phenomena that are responsible for Australia's hydroclimatic variability. This previous work demonstrated how, on average for New South Wales, the probability of a fl ood occurring that is equal in magnitude to the 1-in-100 year flood is about five times greater during La Nina events compared to all other years and 12 times greater during a La Nina event that occurs during the negative phase of the Inter-decadal Pacific Oscillation compared to all other years. This work has recently been extended to focus specifically on urban coastal areas where it has been found that the non-stationarity of flood risk is even further enhanced when compared to the non-coastal catchments. Also investigated is whether this non-stationarity of flood risk is due to non-stationarity of antecedent conditions or non-stationarity of extreme daily and sub-daily rainfall events, with the finding being that both are important. This is contrary to recent studies that claim there is no evidence of non-stationarity in extreme daily and sub-daily rainfall across Australia. The implications of these results are significant given the large populations and infrastructure investment along the eastern seaboard and also timely given current updates to Engineers Australia's Australian Rainfall and Runoff: A Guide to Flood Estimation, the standard for flood estimation in Australia.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Practical responses to water and climate policy
           implementation challenges
    • Abstract: Daniell, KA Water and climate are two of the most important public policy challenges facing Australia. They have pervasive impacts on how and where people can live and what they are likely to be able to do in the future. Policy implementation in these areas suffers from a range of challenges, including how to improve horizon scanning and preparedness, learn from past policy experiences, deal with policy interdependencies, and develop forms of more citizen-centric policy. When these challenges are responded to effectively, it can lead to enhanced foresight and planning, better understanding and communication of policy complexity, and communication of uncertainty and ambiguity, that are key to effective policy implementation. In this context, this paper presents and analyses a number of practical responses to water and climate policy implementation challenges, including the development of 'low regret' policy and infrastructure options that encourage flexibility in responding to possible futures. It also highlights the important role that collaboratively acting now across sectors, issues, governance levels and groups of stakeholders to plan for a range of future scenarios can have on enhancing the capacity of all involved and building pathways to more sustainable and resilient futures.
      PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Instructions to authors submitting to Engineers
           Australia technical journals
    • PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 2 - Abstracts
    • PubDate: Wed, 15 Jan 2014 12:37:13 GMT
       
  • Volume 17 Issue 1 - Instructions to authors submitting to Engineers
           Australia technical journals
    • PubDate: Wed, 25 Sep 2013 16:16:17 GMT
       
  • Volume 17 Issue 1 - Preface
    • Abstract: Phillips, Brett C
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Predictability and chaotic nature of daily streamflow
    • Abstract: Dhanya, CT; Nagesh Kumar, D The predictability of a chaotic series is limited to a few future time steps due to its sensitivity to initial conditions and the exponential divergence of the trajectories. Over the years, streamflow has been considered as a stochastic system. In this study, the chaotic nature of daily streamflow is investigated using autocorrelation function, Fourier spectrum, correlation dimension method (Grassberger-Procaccia algorithm) and false nearest neighbour method. Embedding dimensions of 6-7 obtained, indicate the possible presence of low-dimensional chaotic behaviour. The predictability of the system is estimated by calculating the system's Lyapunov exponent. A positive maximum Lyapunov exponent of 0.167 indicates that the system is chaotic and unstable with a maximum predictability of only 6 days. These results give a positive indication towards considering streamflow as a low dimensional chaotic system than as a stochastic system. Prediction is done using local polynomial method for a range of embedding dimensions and delay times. The uncertainty in the chaotic streamflow series is reasonably captured through the ensemble approach using local polynomial method.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Investigation into probabilistic losses for design
           flood estimation: A case study for the Orara River catchment, NSW
    • Abstract: Loveridge, M; Rahman, A; Hill, P; Babister, M Australian Rainfall and Runoff (Pilgrim, 1987) recommends the design event approach (DEA) as the preferred method for estimating design flood hydrographs, in which a single design event is adopted. More recently, Monte Carlo simulation has been used to allow for the probabilistic nature of input variables in flood modelling. This paper adopts a Monte Carlo framework to evaluate the impact of probabilistic losses on design flood estimates for the Orara River catchment in northeastern NSW. A RORB runoff routing model was used to derive loss values for both the initial loss-continuing loss (IL-CL) and initial loss-proportional loss (IL-PL) models. It has been found that the initial, continuing and proportional losses can be approximated by the Gamma, Weibull and Beta distributions, respectively. When these distributions were compared with non-parametric distributions, differences in the flood estimates were found to be minimal. Another finding was that peak floods estimated using the DEA were more biased for the IL-CL model, than for the IL-PL model. In comparison to the at-site flood frequency curve the IL-CL model produced an overall better fit of the shape of the curve, however, the IL-PL model provided a better fit to the observed flood peaks for mid-range events.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - A standard approach to baseflow separation using the
           Lyne and Hollick filter
    • Abstract: Ladson, AR; Brown, R; Neal, B; Nathan, R The digital filtering approach to baseflow separation suggested by Lyne and Hollick (1979) has been widely used and is available in a number of computer packages. However, details of the approach used by different authors vary and so do the results. This means baseflow volumes and indices reported by different authors, and at different times, are difficult to compare. We propose a standard method for baseflow separation using the Lyne and Hollick digital filter. This includes reflecting the flow series at the start and end of the record to reduce 'warm up' effects and the adoption of specific starting values for each filter pass.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - The development of a new methodology to interpret run
           of river salinity data to assess salt inflow to the River Murray
    • Abstract: Burnell, R; Bekesi, G; Telfer, A; Forward, P; Porter, B In addition to the threat posed by high salinity to drinking water, increased salinity in the River Murray also represents a threat to the health of floodplains, wetlands and may increase the costs of infrastructure maintenance. In the Lower Murray Basin most of the salts in the river originate from groundwater. Run of river salinity surveys are used to measure salt inflow. They measure electrical conductivity every kilometre over five consecutive days, at low and steady river flows. For a robust interpretation of salt inflow, the background electrical conductivity has to be removed from the measurements. The existing methodology is robust for analysing cumulative salt inflows over river reaches but assigns salt inflows up to several kilometres downstream from where they actually occur. A new method has therefore been developed to assign the salt inflow more closely to the location where it actually occurs and at the correct rate. The new methodology is based on the assumptions that salt inflow is the function of space only (during the survey) and the background conductivity can be described by the temporal variations observed at a fixed location. These in turn allow better targeting of the high salt inflow zones for salt interception.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Barriers to voluntary improvement of residential
           fertiliser practices in the Peel-Harvey catchment
    • Abstract: Beckwith, J A; Clement, S The adoption of best practices in residential lawn and garden fertiliser use has been identified as a cost effective means to reduce urban nutrient inputs to waterways. This article examines the barriers to such voluntary change in urban sub-catchments of the Peel-Harvey Estuary system in Western Australia. The implications for the design and successful implementation of a voluntary community-based behavioural change program targeting residential fertiliser practices are discussed.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Value-driven river management: A Murray River case
           study
    • Abstract: Bean, NG; Jewell, ND This paper outlines a quasi-economic hydrological model and management paradigm geared toward public and not-for-profit regulatory bodies, with particular reference to the southern Murray-Darling Basin in southeast Australia. This value-oriented model and paradigm bridges the gap between short-range hydrological forecasting and long-range economic planning. Decision-making is assisted by a scenario-based methodology with a clear distinction between baseline and marginal quantities. The paradigm has applications to seasonal planning, commercial water trading, environmental stewardship and structural adjustment. Specific applications to the Murray-Darling Basin include (i) evaluation of options for infrastructure upgrades and licence buybacks intended to address resource over-allocation, and (ii) revival and rationalisation of hydrological exchange rates for temporary and permanent water trades, with the aim of rigorously accounting for third-party effects.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Applicability of artificial neural network in
           hydraulic experiments using a new sewer overflow screening device
    • Abstract: Aziz, MA; Imteaz, M; Choudhury, TA; Phillips, D During wet weather conditions, sewer overflows to receiving water bodies raise serious environmental, aesthetic and public health problems. These issues trigger the need the most appropriate device/system for a particular installation, especially at unmanned remote locations. A new sewer overflow device consists of a rectangular tank and a sharp crested weir with a series of vertical combs is presented. A series of laboratory tests to determine trapping efficiencies for common sewer solids were conducted for different flow conditions, number of combs layers and spacing of combs. To overcome physical limitations inherent in laboratory studies such as significant cost and time. Artificial neural model was adopted as it has the capacity to accurately predict the outcome of complex, non-linear physical systems with relatively poorly understood physicochemical processes. A series of laboratory tests were conducted with 55 different sets of data. Forty-seven sets of experimental data are used with 60% for training, 20% each for testing and validation of the model. A separate validation data sets were used to judge the overall performance of the trained network. The model can successfully predict the experimental results with more than 90% accuracy with an average absolute percentage error of around 7%.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Impact of dense reservoir networks on water resources
           in semiarid environments
    • Abstract: de Araujo, JC The northeast of Brazil is a semiarid region where water scarcity is a major problem dealt with by the construction of dams. This policy generated a dense reservoir network in the region, resulting in a complex system. The impacts of the network have been assessed, and the results showed that the existence of a large number of small dams upstream the strategic ones, impact both negatively and positively the overall water availability. The negative effects of the network are mainly high evaporation losses from small reservoirs, and the fact that they add considerable complexity to the management of the system. On the other hand, the reservoirs generate a more democratic water distribution and higher energy rationality, as a consequence of the better spatial distribution of the water resources. In addition, sediment retention in the network leads to lower silting rate of strategic reservoirs, meaning lower temporal decay in water availability in the already water-scarce region.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Reducing flood risk associated with basement drainage
    • Abstract: Ladson, AR; Tilleard, J Basements in residential buildings are often subject to flooding. It is common practice to connect basement drainage by gravity to the stormwater system which means that if there is any surcharge caused by capacity constraint, constriction, blockage or partial blockage in the system downstream of where the basement drain connects then the basement is at risk of flooding. This surcharge can lead to water backing up in the drainage pipe and entering the basement. In this discussion paper we comment on flood risk from basement drainage, outline the current guidance and review possible safe drainage solutions.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Abstracts
    • PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 17 Issue 1 - Discussion on 'Design flood estimation in Western
           Australia'. [Book Review]
    • Abstract: French, R Review(s) of: Discussion on "design flood estimation in Western Australia", by D Flavell, Original paper published in Australian Journal of Water Resources, Vol. 16, No. 1, pp. 1-20.
      PubDate: Mon, 23 Sep 2013 10:23:55 GMT
       
  • Volume 16 Issue 2 - Preface
    • Abstract: Phillips, Brett C
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Estimating the change in streamfl ow resulting from
           the 2003 and 2006/2007 bushfires in Southeastern Australia
    • Abstract: Mannik, RD; Herron, A; Hill, PI; Brown, RE; Moran, R Significant bushfires occurred around the Great Dividing Range in south eastern Australia in the summers of 2003 and 2006/2007. The combined scale of these bushfires presents important hydrological implications for the region in the coming decades. This paper reports on results of a project funded by the Victorian Department of Sustainability and Environment to perform a broad-scale assessment of the total water yield impact resulting from the two bushfires. Impacts are estimated in terms of annual changes in streamflow compared to conditions immediately prior to the 2003 bushfire. The modelling approach used to estimate the impacts on streamflow was the Bushfire Impact on Streamflow Yield model. Annual streamflow response curves were produced at each study catchment outlet, as well as spatially explicit datasets showing change in streamflow across the study catchment. Impacts from the two fires were then aggregated to estimate the total change in streamflow yield relative to flows into the River Murray, Eildon Reservoir and the Gippsland Lakes.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Land management impacts on water quality following
           fire in a major water supply catchment
    • Abstract: Wade, A; White, I; Worthy, M; Gill, AM; Mueller, N; Taylor, P; Wasson, RJ Salvage harvesting and land clearance to re-establish radiata plantations in the lower catchment followed the January 2003 bushfires in the Cotter River water supply catchment. We report impacts of post-fire catchment disturbance on water quality and preliminary results of a recently completed works program to improve water quality. Suspended sediment concentrations as high as 39,000 mg/L and massive annual specific sediment yields between 520 and 950 t/km2/a from the 42 km2 salvaged pine area occurred over three low-intensity rainfall years following the fire. In contrast, reservoir turbidity profiles in naturally-regenerated, upper-catchments returned to pre-fire conditions within 12 to 18 months.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Water information services for Australians
    • Abstract: Vertessy, RA On 26 January 2007, following a prolonged period of severe drought and rapidly diminishing water supplies, the Australian Prime Minister announced the National Plan for Water Security, a 10-point plan signifi cantly enhancing Commonwealth involvement in the nation's water affairs. One of the pillars of the reforms was a signifi cant commitment to improve the quality and coverage of Australia's water information. The Bureau of Meteorology was directed to implement the Improving Water Information Program, supported by signifi cant funding and a legislative mandate under the Water Act 2007. This paper traces the evolution of these new water information arrangements and highlights some of the new water information services that have emerged under the program. They include periodic water resource assessments, an annual national water account, various web products summarising the state of our water resources, and a seasonal streamfl ow forecasting service. Like their weather and climate service counterparts issued by the Bureau of Meteorology, these services have some important characteristics, namely that they are enduring, repeatable, robust, trusted and tailored to end user needs. The success of the program to date has been facilitated by appropriate resourcing levels, a clear legislative mandate, high levels of cooperation across the water sector and strong support from the water research and development community.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Image analysis and reconstruction of the 2008 Toga
           River Flash Flood in an urbanised area
    • Abstract: Fujita, I; Kunita, Y; Tsubaki, R In the afternoon of 28 July 2008, a flash flood occurred in the water-friendly reach of the Toga River in Kobe City, tragically drowning five people that included three children. They were among about 50 people enjoying the river environment. The flash flood was caused by sudden localised torrential rain in urbanised area of the small river basin. The onset of the flash flood was captured by a river monitoring camera as consecutive still images, while the surface fl ow just after the peak flow was videotaped by a TV cameraman without using a tripod. In order to estimate the peak discharge of the flash flood, the space-time image velocimetry technique developed by the authors was applied to the video images after applying image stabilisation. The estimated discharge was used as an input hydraulic parameter of the 2D numerical simulation, with a success of reproducing the transient flow pattern observed by the monitoring camera. In addition, the distribution of hydrodynamic force the people in the river were exposed to was calculated to reveal the difficulty of evacuation in flash flood condition, even when the depth of water is less than knee high.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Application of empirical scale correction factors with
           regional flood prediction equations: A case study for eastern Australia
    • Abstract: Zaman, MA; Haddad, K; Rahman, A Regional flood prediction equations are generally developed based on the recorded streamflow data in medium- to large-sized catchments, but these equations are often applied in practice to very small catchments. Since there is little/no recorded streamflow data available for very small catchments, the applicability of the developed regional flood prediction equations to these catchments cannot be verified directly. The empirical observations reveal that smaller catchments produce "steeper flood frequency curves" than larger catchments given all the flood generation factors remaining the same. This paper uses data from 429 catchments from the states of Victoria, New South Wales and Queensland to examine the effects of catchment size on flood quantile estimates. An empirical scale correction factor is proposed that can partially account for the effects of decreasing catchment size on flood quantile estimates. Independent testing using 32 catchments shows that the proposed method provides reasonable results for the catchments as small as 2.3 km2, but its applicability to very small catchments (ie. smaller than 2.3 km2) cannot be verified due to the unavailability of recorded streamflow data.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Flow resistance in four rivers in Victoria, Australia
    • Abstract: Ladson, AR; Lang, SM; Smart, GM; Anderson, BG; Rutherfurd, ID Reach-representative estimates of Manning's n are presented for a range of discharges in four rivers in Victoria, Australia: Acheron River at Taggerty, Merrimans Creek at Stradbroke West, Mitta Mitta River at Hinnomunjie Bridge, and Tambo River at Ramrod Creek. These Manning's n values have been determined from discharge and water surface slope measurements at gauging stations on these four rivers. Manning's n was found to remain almost constant over a range of common discharges, and was found to be a better descriptor of fl ow resistance than Darcy Weisbach f, Chezy C and log-law Zo for these rivers.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Analysis of scour characteristics in presence of
           aerated crossing jets
    • Abstract: Pagliara, S; Palermo, M Jets scour is a major topic in hydraulic engineering. It has to be carefully analysed in order to understand the mechanism and predict its geometry. The jets configuration has a deep influence on the scour features. In the present paper the analysis was conducted in presence of two symmetric crossing jets, varying the discharge, the air content, the tailwater level in the downstream stilling basin, the angle between the jets and the vertical distance of the jets crossing point from the water surface, for different vertical jets angle. It was proven that the presence of the air in the jets deeply affects the scour morphology. The scour geometry was analysed and compared with the respective obtained in black water conditions. Useful practical relationships are proposed to estimate the main scour hole dimensions. The analysis was also extended to non-dimensional profiles and it was proved that the effect of air content on them is negligible.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 16 Issue 2 - Use of the 2-year, 6-hour rainfall in the design of
           erosion control works
    • Abstract: Ladson, AR The design of soil erosion control works often involves the use of the revised universal soil loss equation to estimate potential soil loss (Renard et al, 1991) and the rational method to estimate peak flows (eg. Landcom, 2004). Both these methods require the use of design rainfall intensities but for different purposes. This paper clarifies the use of design rainfall in these approaches, identifies where confusion may occur, and suggests an approach that is consistent with current engineering guidelines.
      PubDate: Wed, 15 May 2013 09:13:15 GMT
       
  • Volume 14 Issue 1 - Addressing Climatic Non-stationarity in the Assessment
           of Flood Risk
    • Abstract: Westra, S; Varley, I; Sharma, A; Hill, P; Jordan, P; Nathan, R; Ladson, A Present-day flood estimation practise is underpinned by the assumption that flood risk in a future climate will reflect historical flood risk as represented by the instrumental record. This assumption, which is commonly referred to as the assumption of stationarity, recently has been questioned as a result of both an increased appreciation of the natural variability in our hydroclimate at temporal scales beyond that of the instrumental record, as well as the projected intensification of the hydrologic cycle due to anthropogenic climate change. These developments have led some authors to suggest that the stationarity assumption should henceforth be considered invalid, thereby calling into question all the methods that are underpinned by it, including flood frequency analysis using observed streamflow records, and rainfall-runoff modelling informed by instrumental precipitation and streamflow records. In this paper we review a wide range of possible sources of non-stationarity in the Australian climate record, and highlight that the primary sources of non-stationarity relevant for flood risk assessments include natural climate modes that vary at timescales similar to the length of the instrumental record, as well as long-term trends and step changes that are attributable to anthropogenic climate change. Although prescriptive guidelines that describe how to address this non-stationarity are currently unavailable in Australia, this review nonetheless highlights the importance of using long records for flood analysis, possibly by extending records using nearby stations. Furthermore, it will become increasingly necessary to develop plausible estimates of how the climate will evolve, and we describe some climate modelling tools that allow for the development of future climate scenarios. Finally, we emphasise that removing the assumption of stationarity will inevitably result in an increase in the uncertainty associated with future flood estimates, and suggest that this may require new methods to conceptualise and manage future flood risk.
      PubDate: Fri, 14 Dec 2012 09:48:11 GMT
       
  • Volume 12 Issue 3 - The Tao of Hydrology and Water Resources: Some
           Philosophical Thoughts
    • Abstract: Daniell, TM This paper provides the thinking that has translated into the Tao of hydrology and water resources. There is a discussion that hydrology is an art born of the observation and investigation of rainfall and runoff. It is emphasised that accurate, relevant and timely information is paramount for decision making in the situation of extreme drought and the threat of climate change. Philosophical thoughts and observations are made on the data processes for decision making, systems thinking and planning in water resources. The need for appropriate models is emphasised, as sophisticated models with uncertain data coming in and certainly uncertain results coming out are no better than a simple model with the same data. Future decision making will be very multidisciplined, and some thoughts on educating the current and future generation of students with skills to cope with this are offered. Throughout, the Tao, an approach to hydrological enlightenment, is given.
      PubDate: Fri, 14 Dec 2012 09:48:11 GMT
       
  • Volume 12 Issue 3 - Preface
    • Abstract: Phillips, Brett C
      PubDate: Fri, 14 Dec 2012 09:48:11 GMT
       
  • Volume 15 Issue 1 - The effect of rainwater tank design on sediment re-
           suspension and subsequent outlet water quality
    • Abstract: Magyar, MI; Ladson, AR; Mitchell, VG; Diaper, C This paper reports the results of laboratory experiments investigating the effect of rainwater tank design on re-suspension of accumulated sediment and the resultant water quality. Twenty-eight different configurations that represented different tank designs in combination with various water levels and quantities of stored sediment were investigated. Re-suspension of sediment was observed during all experiments regardless of the position of the top inlet (whether side or centrally positioned), position of the bottom outlet (50, 100, 200, 400 and 600 mm above the base of the tank), the shape of the tank base (flat or conical), the initial water level in the tank (empty, quarter full or half full), the sediment thickness (10 or 20 mm), the particle size (two particle size ranges) or inflow rate (0.5 or 1.0 L/s). The re-suspended sediment contaminated the out-flowing water, and the greatest impact (worst outcome for water quality) was observed for a centrally located top inlet and an outlet located 50 mm above the tank base. The least contamination of the out-flowing water was observed when the inlet was positioned on the side of the tank. To reduce the potential for contamination of the out-flowing water, it is recommended that rainwater tanks preferably have a side inlet and a conical base, that the sediment thickness in the tank be maintained at low levels by regularly cleaning the tank, and that the tank water be not used during or immediately following rainfall events.
      PubDate: Sat, 6 Oct 2012 14:38:37 GMT
       
  • Volume 14 Issue 1 - CFD Investigation of Turbidity Spikes for Different
           Velocity and Particle Load Profiles in a Horizontal Pipe
    • Abstract: Hossain, A; Naser, J; Imteaz, M A comprehensive 3D numerical investigation of the behaviour of particles flowing through a horizontal pipe has been studied in this paper. The multiphase mixture module available in the computational fluid dynamics (CFD) model FLUENT 6.2 is used in this study. Five different time-dependent flows and particle-load profiles have been used to simulate particle flow behaviour though the pipeline. The deposition of particles along the pipe has been investigated. The effect of unsteady fluid velocity over particle loads has also been investigated. Results show that after a certain length of pipe and/or travel time, when the velocity becomes steady after a deceleration period, the pipe shear stress is strong enough to cause some particle deposition or rolling along the bottom surface of the pipe wall, creating a secondary accumulation of particles (called shoot). Various velocity and particle load profiles have been considered in the light of real phenomena occurring in Melbourne's South East Water Ltd distribution network. The paper is expected to help the water authorities in understanding the propagation of turbidity spikes in pipe networks.
      PubDate: Sat, 6 Oct 2012 14:38:34 GMT
       
  • Volume 12 Issue 2 - Rainwater Tanks and Microbial Water Quality: Are the
           Indications Clear'
    • Abstract: Evans, Craig; Coombes, Peter; Dunstan, Hugh; Harrison, Tracey; Martin, Anthony; Morrow, Abigail Deriving maximum economic and water savings benefits from rainwater harvesting in the urban environment requires the use of rainwater for internal applications, including showering/bathing, laundry and toilet flushing. Widespread use of rainwater for these applications has been hindered by uncertainty over quality and perceptions of health risk. This study examined the presence and abundance of the faecal indicators E. coli, enterococci and total coliform in over 100 water samples collected from rainwater tanks in eastern Australia. A large proportion of samples were compliant with the requirements of mains water drinking standards, especially among those collected via a hot water system, while almost universal compliance with bathing water quality standards was observed. Indicator species were found to represent a very small proportion of total bacterial contamination and no significant correlation between faecal indicator counts and heterotrophic plate counts was observed. Furthermore, enterococci were not significantly correlated with the other indicator groups. On average, heterotrophic counts were found to be dominated by Pseudomonas spp and several other widely distributed environmental organisms. The implications of these findings with regard to the scope of domestic rainwater use in the urban environment, and the difficulty in achieving reliable risk assessment, have been discussed.
      PubDate: Sat, 6 Oct 2012 14:38:31 GMT
       
  • Volume 15 Issue 1 - Comparison of ordinary and generalised least squares
           regression models in regional flood frequency analysis: A case study for
           New South Wales
    • Abstract: Haddad, K; Rahman, A; Kuczera, G Regional flood frequency analysis (RFFA) techniques are commonly used to estimate design floods for ungauged catchments. In Australian Rainfall and Runoff (ARR), the probabilistic rational method (PRM) was recommended for eastern New South Wales (NSW). Recent studies in Australia have shown that regression-based RFFA methods can provide more accurate design flood estimates than the PRM. This paper compares ordinary least squares (OLS) and generalised least squares (GLS) based quantile regression techniques using data from 96 smallto medium-sized catchments across NSW for average recurrence intervals of 2 to 100 years. The advantages of the GLS regression are that this accounts for the inter-station correlation and varying record lengths from site to site. An independent test based on both the split-sample and one-ata-time validation approaches employing a wide range of statistical diagnostics indicates that the GLS regression provides more accurate flood quantile estimates than the OLS one. The developed regression equations are relatively easy to apply, which require data for only two to three predictors, catchment area, design rainfall intensity and stream density. The findings from this study together with those from other RFFA studies being examined as a part of ARR upgrade projects will inform the development of RFFA techniques for inclusion in the revised edition of ARR.
      PubDate: Sat, 6 Oct 2012 14:36:24 GMT
       
  • Volume 14 Issue 2 - Design Flood Estimation in Ungauged Catchments: A
           Comparison between the Probabilistic Rational Method and Quantile
           Regression Technique for NSW
    • Abstract: Rahman, A; Haddad, K; Zaman, M; Kuczera, G; Weinmann, PE Design flood estimation for ungauged catchments is often required in hydrologic design. The most commonly adopted regional flood frequency analysis methods used for this purpose include the index flood method, regression based techniques and various forms of the rational method. This paper first examines the similarities and differences between the probabilistic rational method (PRM) (the currently recommended method for Victoria and eastern NSW in Australian Rainfall and Runoff) and the generalised least squares (GLS) based quantile regression technique (QRT). It then uses data from 107 catchments in NSW to compare the performance of these two methods. To make a valid comparison, the same predictor variables and data set have been used for both methods.
      PubDate: Sat, 6 Oct 2012 14:36:23 GMT
       
  • Volume 14 Issue 1 - Regionalisation of Skew for Flood Frequency Analysis:
           A Case Study for Eastern NSW
    • Abstract: Haddad, K; Zaman, M; Rahman, A In flood frequency analyses, skew plays an important role in characterising the tails of the flood frequency distributions for which a three-parameter distribution like Log-Pearson Type 3 (LP3) is often preferred over two-parameter distributions. For fitting the LP3 distribution to a station's data, an estimation of skew is needed. Since the length of streamfl ow data is limited for the majority of stations in Australia, the at-site estimation of skew is highly uncertain. To overcome this problem, the use of regional skew has been advocated, however, this has not been well investigated with Australian data. This paper presents a Bayesian generalised least squares (B-GLS) regression approach to regionalise the skew coefficient for eastern NSW. It has been found that the B-GLS regression approach is quite capable of providing stable estimation of skew, which is equivalent to an at-site skew estimator based on over 90 years of data. The results of this study suggest that the B-GLS model can provide an avenue to develop a regional skew map for Australia using the national database being prepared as a part of the on-going revision of Australian Rainfall and Runoff.
      PubDate: Sat, 6 Oct 2012 14:23:28 GMT
       
  • Volume 15 Issue 1 - Establishment of environmental water in the Murray-
           Darling Basin: An analysis of two key policy initiatives
    • Abstract: Horne, A; Freebairn, J; O'Donnell, E Policy to protect river ecosystems has changed rapidly in Australia, and the mechanisms to both establish and manage environmental water are still evolving. Policy has moved from providing a fixed environmental target (albeit varying between years) to one in which the environment can actively participate in the market, with the possibility of better fulfilling variable water requirements. However, the inherent nature of the sustainable diversion limit (SDL), established under the Water Act 2007, is that it represents a fixed allocation to the environment. This paper considers the interaction of the new SDL for the Murray-Darling Basin and potential issues arising from the interaction with the government buyback initiative. While both the SDL and buyback have been discussed extensively, the interaction between the two policies has received little debate. Pairing these two policy initiatives will have implications for the flexibility of management of the environmental water, and the ability for on-going trade between the environment and consumptive water users. Our position is that the SDL, or preferably rules-based water, should reflect an absolute minimum limit on environmental water requirements, while the buyback should provide the environmental water as tradable water rights with the flexibility to respond to shifts in the environmental water demand curve by providing environmental water over and above the SDL. If both a buyback and minimum flow rules are in place, the SDL will provide little additional benefits but increase administrative costs and reduce flexibility. This has significant implications for the way the SDL and buyback strategy are structured.
      PubDate: Sat, 6 Oct 2012 13:35:49 GMT
       
  • Volume 16 Issue 1 - Water-sensitive cities: Applying the framework to
           Melbourne
    • Abstract: Lloyd, S; Wong, T; Blunt, S Key thinkers have been developing a strategic framework for transforming cities into water-sensitive cities. Transforming Melbourne into a water-sensitive city has been a focus of the City of Melbourne through undertaking an integrated water management strategy coined "city as a catchment", and is being progressively undertaken by other local municipalities. Critical to applying the framework has been to establish water quality and water conservation targets that councils are able to commit to. The paper outlines a key approach adopted to diversify water supply options through the provision of both centralised and decentralised water schemes, ranging from the simple rainwater tank for non-potable use to large scale stormwater harvesting schemes. Stormwater not harvested is treated to improve its quality prior to discharge to the environment for the protection of aquatic ecosystems. The paper presents an overview of the implementation plan for the City of Melbourne that clearly establishes a vision for the city and demonstrates how selection of on-ground works relate to water conservation, best practice stormwater management targets and wastewater minimisation. This includes implementing sustainable urban water management approaches across all of the city's assets (including parks and gardens, building and roads). In implementing the framework, Council's influence would extend adoption beyond the public domain by facilitating private participation through regulations and provisions of incentives for the uptake of WSUD in the private domain (including commercial and residential sites).
      PubDate: Wed, 26 Sep 2012 16:10:30 GMT
       
  • Volume 16 Issue 1 - Evaluation of an evaporation suppressing monolayer
           system in a controlled wave tank environment: A pilot investigation
    • Abstract: Schouten, P; Putland, S; Lemckert, C; Underhill, I; Solomon, D; Sunartio, D; Leung, A; Prime, E; Tran, D; Qiao, G Due to long-term drought conditions coupled with the apparent influence of global warming, compounding water loss has been a very serious issue across the vast majority of the Australian continent. During these drought conditions, the evaporative effect outweighs the amount of precipitation being received on a year to year basis. Several methods have been introduced in recent history to inhibit the amount of evaporative loss from various types of water bodies such as the application of thin layer chemical films (monolayers). A series of solvent, solid and suspension derived prototype monolayers, based on ethylene glycol monooctadecyl ether (C18E1), are examined in this current study as an approach to eliminate the problems seen to occur with the previous types of monolayers. This research evaluates the fundamental effect of wind and wave based activity upon these prototype monolayers in an atmospherically controlled enclosure positioned over a large extended water tank using real-time environmental measurements. Selected performance results for the prototype monolayers as measured within the enclosed water tank were compared to results measured from a control monolayer film based on a commonly used octadecanol suspension film. The results show that under varying wind and wave conditions the prototype monolayers inhibit evaporation at a level similar to or better than the octadecanol standard, even when delivered at lower raw dosages.
      PubDate: Wed, 26 Sep 2012 16:10:13 GMT
       
  • Volume 16 Issue 1 - Predicting groundwater response times and catchment
           impacts from land use change
    • Abstract: Beverly, C; Hocking, M Natural resource managers are becoming increasingly interested in incorporating into policy and investment frameworks the likely lag between land use change and groundwater response time. Until recently, predicting the response times of groundwater systems to a range of investment strategies (eg. agronomic changes and recharge management options) has relied on bounded analytical solutions or empirical observations from limited transect monitoring trials. This paper describes and evaluates an approach to estimate spatial groundwater response times to changes in groundwater recharge from land use and/or climate change. The approach is based on linking an unsaturated catchment model to a multi-layered distributed groundwater model and was applied to the upper Loddon Catchment (6113 km2) in southwestern Victoria, Australia. The objectives of this paper are to (i) present spatial and temporal variation estimates in groundwater response times and (ii) identify locations in the landscape which have the greatest impact on watertable level. The modelling approach presented in this paper demonstrates the capacity to link a suite of farming system models into a catchment framework to derive spatially explicit recharge estimates which are integrated into a distributed groundwater model. In combination with the catchment depth to watertable impact mapping, the response time predictions derived using this modelling approach offer robust estimates of storage-discharge characteristics of catchments in contrast to idealised groundwater analogues which were found not to adequately capture complex groundwater interactions and within-catchment dynamics.
      PubDate: Wed, 26 Sep 2012 16:07:19 GMT
       
  • Volume 16 Issue 1 - Design rainfall temporal patterns in Australian
           'Rainfall and Runoff': Durations exceeding one hour
    • Abstract: French, R; Jones, M The current edition of Australian Rainfall and Runoff espouses the design event approach in which a single flood is the "event" with which the hydraulic structure is expected to cope during its working life. The uniform rainfall of the selected average recurrence interval requires a temporal pattern before input to a catchment model. Australian Rainfall and Runoff provides temporal patterns for each of eight defined zones, with 20 specific durations and two classes of average recurrence interval. These patterns are inconvenient to use, especially for other than specified storm durations, and at zone boundaries when differently-shaped patterns apply. This paper shows that distinctions between zones and average recurrence intervals are not significant. Only two of the 144 temporal patterns for durations 1.5 to 24 h are significant in flood design practice, and these are replaced with continuous equations that allow design storm durations to be divided into any number of increments.
      PubDate: Wed, 26 Sep 2012 16:05:35 GMT
       
  • Volume 16 Issue 1 - Design flood estimation in Western Australia
    • Abstract: Flavell, D This paper provides details of flood frequency procedures developed for the Pilbara, Kimberley, Wheatbelt and Goldfields regions of Western Australia, which should provide better estimates of design floods than the methods recommended in the 1987 version of Australian Rainfall and Runoff. The first section of the paper discusses the adequacy of the stream flow data on which the regional flood frequency procedures (RFFPs) are based and identifies the large extrapolation of the gauging station rating curves and the general underestimation of the magnitude of larger flood events. This leads to the conclusion that a conservative approach is required when developing a RFFP. A description of the general approach taken in developing the RFFPs is then given. Details of the RFFPs developed for each region follow and finally a comparison is made between the magnitudes of the floods in each region.
      PubDate: Wed, 26 Sep 2012 16:04:26 GMT
       
  • Volume 16 Issue 1 - Discussion on "Flood frequency and design flood
           estimation procedures in the United States: Progress and challenges" by JF
           England, Jr
    • Abstract: French, R With revision of Australian Rainfall and Runoff under way, it is heartening to read of others headed in the direction of improvement to hydrologic design techniques.
      PubDate: Wed, 26 Sep 2012 16:03:29 GMT
       
  • Volume 16 Issue 1 - The hydrologic impacts of farm dams
    • Abstract: Nathan, R; Lowe, L Farm dams play an important role in Australian life. Small dams storing just a few megalitres provide essential supplies for stock and domestic consumption. Larger dams are used for irrigation purposes, and play a vital role in increasing the productivity, and hence viability, of many agricultural enterprises. Dams are also constructed for recreational and ornamental purposes, for aquaculture, and as artificial wetlands for environmental purposes. Over time there has been an increase in the number of dams used for irrigation purposes. There has been a general trend towards constructing larger dams, some impounding many hundreds of megalitres, to provide additional security of supply and to irrigate high value crops. An increase in the number of farm dams used for domestic, stock or aesthetic purposes is also expected in new peri-urban developments.
      PubDate: Wed, 26 Sep 2012 16:01:59 GMT
       
  • Volume 16 Issue 1 - Preface
    • Abstract: Phillips, Brett C
      PubDate: Tue, 25 Sep 2012 10:30:18 GMT
       
  • Volume 14 Issue 2 - Discussion on 'Addressing Climatic Non-stationarity in
           the Assessment of Flood Risk'
    • Abstract: French, R Practitioners will have to express their design uncertainties more often and more clearly. Previous editions of Australian Rainfall and Runoffhave been written in language to engender confidence in flood numbers and the producers thereof, so expressions of uncertainty are almost totally absent from its pages.
      PubDate: Wed, 19 Sep 2012 12:28:34 GMT
       
  • Volume 14 Issue 2 - Preface
    • Abstract: Phillips, Brett C
      PubDate: Wed, 19 Sep 2012 12:28:34 GMT
       
  • Volume 15 Issue 2 - Model comparisons for tracer experiments at a clear
           water storage tank
    • Abstract: Crowther, JM; Dandy, GC A fluoride tracer experiment was conducted to investigate mixing processes and residence times in a cylindrical clear water storage tank at the Stromlo Water Treatment Plant, Canberra, ACT. Four different modelling techniques have been used to simulate the experimental results: computational fluid dynamics (CFD), a single continuously stirred tank reactor (CSTR), two CSTRs in series, and a series/parallel combination of two CSTRs (NM). Flow of a conservative tracer through the tank has been simulated at the rated flow from the works using the PHOENICS (CFD) program. The CFD simulation agrees closely with the measured fluoride concentrations and requires no fitted parameters. The agreement with the experimental data for NM is comparable with the CFD and a little better than two CSTRs in series. The poorest agreement was obtained with a single CSTR model.
      PubDate: Thu, 19 Jul 2012 13:48:44 GMT
       
  • Volume 15 Issue 2 - Social considerations in domestic water pricing: A
           case study of Perth, Western Australia
    • Abstract: Wasimi, SA; Hassa, S Domestic water pricing is a challenging balancing act of the three critical dimensions of sustainability: economic, environmental and social objectives (OECD, 2010). The increasing block tariff approach to water pricing is growing in popularity throughout the world because, arguably, it is seen to best address all three dimensions. However, social equity considerations are often at odds with other criteria and needs special scrutiny, as affordability and equity aspects may not be properly addressed especially when income and household size are not accounted for. This paper looks at social considerations that are relevant for decision making in water pricing for the city of Perth, Western Australia and proposes a pricing scheme that would address the social issues satisfactorily. The optimisation model, particle swarm optimisation, which has been used in this study can also be applied when multiple objective functions that include other considerations such as economic efficiency and environmental sustainability are used.
      PubDate: Thu, 19 Jul 2012 13:48:44 GMT
       
  • Volume 15 Issue 2 - Design criteria for channel-forming flows in waterways
           of urbanising catchments
    • Abstract: Argue, JR; Pezzaniti, D; Hewa, GA Adequate consideration of the joint problems of natural channel stability and bio-community preservation in greenfield catchments experiencing development has been lacking in the WSUD (water sensitive urban design) guidelines promoted in eastern and southern Australia in recent years. The paper offers retention technology as a vital ingredient of catchment management, enabling urbanisation to proceed with minimum loss of waterway environmental values.
      PubDate: Thu, 19 Jul 2012 13:48:44 GMT
       
  • Volume 15 Issue 2 - Estimation of mean annual runoff across Southeast
           Australia by incorporating vegetation types into Budyko framework
    • Abstract: Zhang, Y; Chiew, FHS This paper uses the Budyko and Fu models to estimate mean annual runoff in 0.05 degrees grid cells across southeast Australia, and assesses the estimates against observations in 323 catchments. The results show that the Budyko model can provide reasonable estimates of runoff and is suitable for data limited regions. In regions where there are some streamfl ow data available, the calibration of a single parameter in the Fu model gives better runoff estimates than the Budyko model and similar to regionalised rainfall-runoff models. In drier regions, the consideration of different vegetation types in the Fu model can improve the modelling results.
      PubDate: Thu, 19 Jul 2012 13:48:44 GMT
       
  • Volume 15 Issue 2 - Drought assessment and forecasting: A case study on
           the Yarra river catchment in Victoria, Australia
    • Abstract: Barua, S; Ng, AWM; Perera, BJC Drought is a natural phenomenon, and has widespread and significant impacts on the world's economy, environment, industries and the wider community. Early detection of droughts helps to implement drought mitigation strategies and measures before they occur. Therefore, drought forecasting plays an important role in the planning and management of water resources systems, especially during dry climatic periods. However, drought assessment and forecasting are not always easy tasks. In this paper, an approach that was developed and tested for drought assessment and forecasting is presented together with a case study on the Yarra River catchment in Victoria (Australia). An evaluation of existing drought indices was first conducted in this study, which led to the development of a new non-linear aggregated drought index (NADI). The NADI defines a broad perspective of dryness within the catchment rather than the traditional individual meteorological, hydrological and agricultural subcategories. Thereafter, a novel drought forecasting modelling approach was developed using the NADI time series. The results show that the developed forecasting models are capable of forecasting drought conditions well up to 6 months ahead forecasts which were statistically significant at 1% level. The outcomes of this study will be useful for water resources managers to assess droughts effectively and forecast future drought conditions, which will allow them to plan ahead the future water management activities especially during drought periods.
      PubDate: Thu, 19 Jul 2012 13:48:44 GMT
       
  • Volume 12 Issue 3 - Flash Flood Forecasting Combining Meteorological
           Ensemble Forecasts and Uncertainty of Initial Hydrological Conditions
    • Abstract: Philipp, Andy; Schmitz, Gerd H; Krube, Thomas; Schutze, Niels; Cullmann, Johannes Flood forecasting for fast responding catchments encounters problems, especially in terms of short warning periods and a very limited reliability. Within a new stochastic framework based on rigorous rainfall-runoff modelling and Monte Carlo simulations, we consider uncertainties of two sources: (i) uncertainty from the estimation of initial hydrological conditions, and (ii) the uncertainty of the meteorological rainfall forecast. We avoided the high computational demand of extensive Monte Carlo simulations by using a symbiosis between physically-based hydrological modelling and computationally highly efficient artificial intelligence techniques. The new PAIOFF methodology (Process Modelling and Artificial Intelligence for Online Flood Forecasting; see Schmitz et al, 2005, and Cullmann, 2006) employs a physically-based hydrological/hydraulic model of the considered catchment for generating, in a first step, the complete range of realistic possible flood scenarios on the basis of a catchment specific meteorological analysis. The resulting database of corresponding input/output vectors - supplemented by generally available hydrological and meteorological data for characterising the catchment situation prior to a storm event - serves, in a second step, for setting up a set of task-specific artificial neural networks (ANN), which finally portray both the rainfall-runoff process and the hydrodynamic flood wave propagation in the river. We subsequently use this tool for investigating the global uncertainty of flash flood forecasting in a small- to medium-sized catchment on the basis of a comprehensive Monte Carlo analysis. Along these lines, the computationally highly efficient PAI-OFF technique allowed performing an extensive number of runs for obtaining ensembles of predicted stream flow that can be used to evaluate probabilities of exceedance of critical river stages/flows via an integration of both the hydrological uncertainty and the meteorological uncertainty. This approach was then implemented and applied to the Freiberger Mulde catchment in the Ore Mountains in Eastern Germany (with an area of about 3000 km2). The results of the overall ensemble predictions in the form of the ensemble mean values unveiled an astonishing underestimation of the recorded flood peak - most due to the bias of the considered initial hydrological conditions.
      PubDate: Mon, 2 Jul 2012 14:07:56 GMT
       
  • Volume 12 Issue 2 - An Integrated Approach to Water Conservation for Large
           Users
    • Abstract: Werner, Melanie; Hauber-Davidson, Guenter Water conservation programs targeted at large users will play an integral role in securing water supplies for Australian cities in years to come. A hierarchical approach to water conservation - reducing consumption as a priority, then considering internal reuse of water and replacement of potable water with alternative sources - should be the key principle in sustainable water management. The application of this approach relies on a sound understanding of water consumption at a site: where water is used, why, when and how. This entails sub- and smartmetering of the water supply, and detailed analysis of site activities to produce a robust site water balance. The hierarchical approach can then be applied, and conservation options can be costed to assess financial viability. "Packaging" measures with different payback times together should be considered, along with funding support available. Based on implemented projects, an estimated 30% of potable water consumption within the commercial and industrial sectors could be saved at attractive payback periods. By adopting this sensible, integrated water conservation and management approach, the same outcomes can be achieved with less potable water consumption. Appropriate source substitution is a pillar of sustainable water supply, providing water at less environmental, social and financial cost than the alternatives.
      PubDate: Fri, 29 Jun 2012 16:32:36 GMT
       
  • Volume 12 Issue 3 - Investigating Spatial and Temporal Variability in
           Runoff and Sediment Generation Using a Physically-based Model, Thales
    • Abstract: Adams, R; Western, A; Anderson, B; Seed, A Limited within-day rainfall data availability has led to a paradigm of daily hydrological modelling that conflicts with key process timescales, resulting in poor modelling of runoff and particularly erosion. A new hydrological modelling framework that accounts for variation in rainfall, runoff and erosion across the landscape, and within each day using a statistical approach, has been developed. The ultimate aim is to develop a model for estimating runoff and erosion that is consistent with key process time and space scales. Central to this aim is to be able to run the model using daily precipitation data with a distribution function (DF) model to account for subdaily variations in precipitation and with an algorithm that accounts for routing processes in the catchment. A series of DF models have been developed based on 6-minute interval precipitation data from pluviographs at the point scale. This paper provides insight into the effects of scaling up from hillslopes to whole catchments, with the results to underpin an extension of the existing point-scale models to catchment scale. An analysis framework that allows the various effects to be separated was developed. The Thales physically-based hydrological model was employed with gridscale (25 m2) runoff and sediment generation processes of varying complexity specified. A series of simulations was performed to investigate both the temporal and spatial effects of rainfall and catchment variability on runoff and erosion generation. The results were analysed and compared across different scales to determine whether the scaling of rainfall in space and time could be linked to the scaling of runoff and erosion. In addition, the results were examined to identify an approach to account for the routing effects that become important in medium-sized catchments.
      PubDate: Fri, 29 Jun 2012 16:30:30 GMT
       
  • Volume 12 Issue 3 - Spatially Explicit Modelling of the Hydrologic
           Response of Bushfires at the Catchment Scale
    • Abstract: Hill, Peter I; Mordue, Anna; Nathan, Rory J; Daamen, Carl C; Williams, Katherine; Murphy, Rachel E This paper reports on a broad-scale assessment of water yield impacts of the 2003 Alpine bushfires, which burnt over 1 million ha across northeastern Victoria and southern NSW, including catchments of a number of key water storages, such as Hume and Dartmouth Dams, and also the Gippsland Lakes. A new model - Bushfire Impact on Streamflow Yield (BISY) was developed to estimate the change in streamflow. Streamflow response curves were derived for the different species, which were based upon recorded streamflows and transposed based upon the mean annual rainfall. The impact on streamflow was estimated for 12 catchments ranging in size from approximately 500 to 10,000 km2. For each catchment an annual streamflow response curve was produced at the catchment outlet, as well as spatially explicit data sets showing change in streamflow across the catchment. The results were aggregated to estimate the total change in mean annual streamflow for the River Murray and Gippsland Lakes.
      PubDate: Fri, 29 Jun 2012 16:30:16 GMT
       
  • Volume 12 Issue 3 - Quantifying the Impacts of Rainwater Harvesting in a
           Case Study Catchment: The Arvari River, Rajasthan, India
    • Abstract: Glendenning, Claire; Vervoort, RWillem Rainwater harvesting (RWH) is the collection and storage of runoff for the primary purpose of groundwater recharge in arid and semi-arid regions of India. In India, investment in RWH for groundwater recharge is increasing. However, despite this very little is known on the catchment hydrological impacts of RWH. Although RWH is a small-scale operation, when implemented across a catchment, the impact on groundwater and river flow could be significant. However, there is currently no study that has comprehensively quantified this impact. This paper therefore proposes a method to explore the effects of RWH in a case study catchment of the 500 km2 ungauged Arvari River Basin in Rajasthan, India, where 366 RWH structures have been built since 1985. Difficulties associated with working in semi-arid regions, such as this catchment, include the high spatial and temporal variability of climate, particularly rainfall, and landscape conditions and data scarcity. Detailed field studies of local scale effects of RWH and recharge under a number of structures were studied during the monsoon of 2007 in the catchment. Discharge over anicuts on the river was also monitored and subsequent water level rise in wells. These results will be extended to the catchment scale using a conceptual catchment water balance model that captures the main hydrological processes. Water moves through the catchment in a series of linked storages for each land use, where the upper and lower catchments are separate domains. The groundwater system consists of an unconfined alluvial aquifer over a confined hard rock aquifer. This will allow different scenarios of land use and levels of RWH to be explored to quantify the hydrological impact on the catchment.
      PubDate: Fri, 29 Jun 2012 16:30:07 GMT
       
  • Volume 12 Issue 3 - Application of Ensemble Kalman Filter for Flood
           Forecasting in Australian Rivers
    • Abstract: Srikanthan, R; Amirthanathan, GE; Kuczera, George There is a growing interest in understanding the uncertainty in flood forecasting and the resulting flood warnings. This is borne out of the fact that the processes involved in flood forecasting have inherent uncertainties in them. The procedure used in flood forecasting consists of a number of steps. The first step is rainfall measurement and forecasting rainfall during a flood event. The rainfall is then transformed into flow using a combined water balance and runoff-routing model. There are uncertainties associated with rainfall measurement/forecasting, model (conceptualisation and parameters) and flow measurements. All these uncertainties contribute to the uncertainty in the resulting flood forecasts. The Ensemble Kalman Filter (EnKF) enables all these uncertainties to be combined in a systematic way and it has been used by a number of researchers in the past. In this paper, the EnKF with state and parameter updating is used with the Probability Distributed Moisture model to forecast flood events in six rivers located in different parts of Australia. The results showed that the quality of forecasts deteriorated with lead time greater than 6 hours and the peak discharge magnitudes were underestimated. Of the two variations used, state updating performed better than parameter updating.
      PubDate: Fri, 29 Jun 2012 16:29:49 GMT
       
  • Volume 14 Issue 2 - In Search of the Best
    • Abstract: Dandy, G This paper is based on the 2009 Munro Oration given by Prof Graeme Dandy at the 32nd Hydrology and Water Resources Symposium held in Newcastle on 30 November to 3 December 2009. The paper outlines the importance of considering human activity and its impact on the hydrological cycle. It outlines the systems approach, multi-objective planning and evolutionary optimisation, and their application to the planning and design of water resources systems. The contribution of previous researchers and engineers in the development of these techniques is acknowledged. Among them, Crawford Munro provided a shining example of a rational approach to the planning and management of our water resources.
      PubDate: Fri, 29 Jun 2012 16:27:18 GMT
       
  • Volume 15 Issue 2 - The non-impact of debris blockages on the August 1998
           Wollongong flooding
    • Abstract: French, R As part of the revision of Australian Rainfall and Runoff, Working Party 11 - Debris Blockage of Waterways is determining how flood-mobilised debris might best be accounted for in the design of the waterway openings of hydraulic structures. The claim of much data on debris blockage of drainage structures in the 1998 Wollongong flooding has been examined, and the finding is that none of that event's data quantifies the degree of hydraulic blockage of waterways by debris.
      PubDate: Fri, 29 Jun 2012 16:10:41 GMT
       
  • Volume 15 Issue 2 - Discussion on "Incorporating drought management
           planning into determination of yield" by B Berghout
    • Abstract: French, R Review(s) of: Having worked in an era when hydrologists were unconcerned with water policy, water management or water environment, this writer was interested in tackling a paper on a water delivery technology.
      PubDate: Fri, 29 Jun 2012 15:50:40 GMT
       
  • Volume 15 Issue 1 - Calibration and sensitivity analysis of urban drainage
           models: MUSIC rainfall/runoff module and a simple stormwater quality model
           
    • Abstract: Dotto, CBS; Deletic, A; McCarthy, DT; Fletcher, TD Model calibration and sensitivity analysis of stormwater models are required to assess model performance; it is very unlikely that non-calibrated models will lead to reasonable results. The aim of this paper is to present results of the calibration and sensitivity analysis of the key parameters used in flow modelling by MUSIC and parameters of a simple stormwater quality model. The assessment of the models is undertaken using a Monte Carlo Markov Chain approach. We describe the models' performance, provide information on their sensitivity to parameters and also discuss the correlation between these parameters. This work will help practitioners to understand importance of the MUSIC parameters that they usually use without calibration. The information reported in the results will also help to guide future development of stormwater quality models and the data needed to support it.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 15 Issue 1 - Regional flood frequency for Queensland using the
           quantile regression technique
    • Abstract: Palmen, LB; Weeks, WD; Kuczera, G Design flood estimation for small- and medium-sized catchments is a frequent requirement for a wide range of projects. While each individual project in this category is likely to be relatively small, the total value of projects that rely on design floods for the design is very high. The currently adopted approaches for Queensland are published in Australian Rainfall and Runoff. Several approaches are described, though the Main Roads Rational Method (MRRM) is predominant in practice. This method has been used throughout Queensland for many years, but the basis of the method is not considered reliable because of the lack of recorded data used in the development and the lack of independent testing. The development of the new procedure described in this paper has used all suitable streamflow data available for the state. It therefore has a better foundation and the results can be accepted with more confidence. The approach presented uses the quantile regression technique to develop a procedure for calculating design floods for ungauged catchments that relates the design flood discharges to readily available catchment characteristics. The method is then tested against the currently available MRRM. This paper provides an input to part of the upgrade of Australian Rainfall and Runoff, currently underway.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 15 Issue 1 - Flood frequency and design flood estimation procedures
           in the United States: Progress and challenges
    • Abstract: England, JF Design flood estimation procedures in the United States have traditionally focused on two primary methods: frequency analysis of peak flows for floodplain management and levee design; and deterministic, probable maximum flood (PMF) estimates for design of dams and nuclear facilities. Federal Agencies in the United States, including the Bureau of Reclamation, US Geological Survey and Army Corps of Engineers, are currently examining potential changes to these standard flood hydrology procedures. This paper presents overviews of some ongoing investigations and data collection studies to support potential changes in design flood estimation. For floodplain management, the current guideline is Bulletin 17B, which specifies the use of an LP3 distribution, method of moments and regional skew information. Potential improvements to Bulletin 17B currently under consideration are: (i) use of historical and paleoflood information; (ii) adjusting for low outliers; (iii) improved plotting positions; and (iv) confidence intervals. Ongoing testing results are presented, highlighting the expected moments algorithm. In contrast to well-established, deterministic (PMF) extreme flood estimates for dam safety, agencies are now moving toward risk-based techniques. The Bureau of Reclamation has developed and applied several methods in order to estimate extreme floods and probabilities for large dams. Techniques used to date are summarised, along with those being considered by other US agencies. Improvements to extreme flood databases that provide inputs, including extreme storms and probable maximum precipitation estimates, precipitation frequency and paleofloods, are ongoing. Some challenges to updating design flood methods and data, including institutional effects, national scale, research to operations and use of new technologies, are described.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 15 Issue 1 - Coping with severe drought: Stories from the front
           line
    • Abstract: Barton, AF; Briggs, S; McRae-Williams, P; Prior, D The last 12 years has seen extreme drought in western Victoria. This has impacted on the area in many ways, but none more so than in the provision of basic water supplies to people. To meet the challenge of drought, headworks storages have had to be operated at record low levels, severe water restrictions imposed, water carting programs established, alternative sources of water, and new technologies developed and used. Significant changes have also been made to the water supply infrastructure in the region, most notably the Northern-Mallee and Wimmera-Mallee Pipelines. This paper relates the story of how water resources were managed and bulk water was delivered to around 70,000 customers over a geographic spread of 62,000 km2, or about 30% of Victoria. Discussion on the social, environmental and economic impacts on the region are also provided.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 15 Issue 1 - Water: A personal matter
    • Abstract: Askew, AJ This paper is a summary of the Munro Oration delivered in Brisbane on 29 June 2011. It presents water as an extraordinary substance that is critical to our very existence and therefore demands of us both respect and commitment to its protection and wise management. It argues for a balanced approach to establishing water programs in which research, teaching, practical application, funding and governance all have a role to play. It outlines the value of personal contacts within the freshwater community and calls for the Australian members of that community to be active at both national and international level in promoting Australian expertise and in learning from that of other countries.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 15 Issue 1 - Preface
    • Abstract: Phillips, Brett C
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 2 - Modelling the Environmental Water Reserve: A Case
           Study Exploring the Effects of the Environment's Water Entitlement in a
           Complex Water Supply System
    • Abstract: Godoy, W; Barton, AF The objective of the present study was to demonstrate the effect the environment's entitlement configuration has on the volume of water supplied to the environment, and the overall efficiency of the water supply system under the historic climatic sequence and climate change. The modelling work is undertaken using the REALM simulation package, with the results presented in case study form based on the Wimmera-Mallee system, outlining the changes in the total system water balance post-Wimmera Mallee Pipeline, changes in the environment's reliability of supply, and exceedance plots for environmental flows and headworks loss. The outcomes of this study demonstrate the need to consider the trade-offs between large entitlements of low reliability and small entitlements of high reliability as part of the system reconfiguration process, given the effect it has on total system efficiency, particularly in an uncertain climate future.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 2 - Sensitivity Analysis of Yield Estimate of Urban Water
           Supply Systems
    • Abstract: King, DM; Perera, BJC Sensitivity analysis (SA) theory and techniques were used in this study to estimate the sensitivity of input variables on the yield estimate of an urban water supply system. The SA techniques considered were Morris method and Fourier amplitude sensitivity test (FAST), including the related extended FAST. A case study on a simple urban water supply system was conducted to assess the applicability and to study the limitations of these techniques and the SA framework adopted. Findings showed that the streamflow dominated all experiments, with the supply reliability threshold, the upper restriction rule curve and the consecutive months in restrictions threshold of subsequent importance. In a screening pass, importance ranking of the 26 considered variables from the Morris method were verified with FAST and extended FAST.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 2 - Estimation of Major Floods: Applicability of a Simple
           Probabilistic Model
    • Abstract: Haddad, K; Rahman, A; Weinmann, PE Estimation of major flood flows is needed in the design and operation of large water infrastructure. This paper presents a simple probabilistic model (PM) that can be used to derive 'easy to apply' prediction equations for estimation of major flood flows. The proposed method assumes that the maximum observed flood data over a large number of sites in a region can be pooled together by accounting for the across-site variations in the mean and standard deviation values. The method is developed and tested in this paper using data from 227 catchments across Victoria and NSW. The application to ungauged catchments involves the development of prediction equations using generalised least squares regression for the mean and coefficient of variation of the annual maximum flood series as a function of catchment characteristics.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 2 - Rainfall-runoff Modelling across Southeast Australia:
           Datasets, Models and Results
    • Abstract: Vaze, J; Chiew, FHS; Perraud, J-M; Viney, N; Post, D; Teng, J; Wang, B; Lerat, J; Goswami, M This study describes a daily rainfall, potential evaporation and streamflow data set compiled for the important water resources region of southeast Australia, and the application of six commonly used lumped conceptual rainfall-runoff models to estimate daily runoff across the region. The daily climate data set and the daily modelled runoff are available from 1895 to 2008 at 0.05 grid resolution across the region. The modelling exercise indicates that the rainfall-runoff models can generally be calibrated to reproduce the daily observed streamfl ow (for 232 catchments in the high runoff generation areas), and the regionalisation results indicate that the use of optimised parameter values from a gauged catchment nearby can model runoff reasonably well in the ungauged areas. There are differences between the six models, but they are relatively small when used to describe aggregated results across large regions.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 2 - Rainfall Energy Loss: An Empirical Model
    • Abstract: Pudasaini, MS; Shrestha, SP Kinetic energy of a rainfall event is determined by its intensity. However, the effective kinetic energy reaching a soil surface that is responsible for detachment and transportation of soil particles is often less than the total kinetic energy of the rainfall event. This is because of the cushioning effect a film of water provides. Therefore it is essential to account for the loss in kinetic energy of a rainfall event and incorporate it in simulation models to accurately estimate soil erosion. This paper proposes a logarithmic energy loss model to estimate kinetic energy of rainfall reaching the soil surface. The model accounts for the depth of shallow overland flow and rainfall intensity. The empirical model was established through the set of data obtained from a rainfall simulation experimental setup consisting of a laboratory-scale tilting hydraulic flume, rainfall simulator and a series of sensitive piezoelectric force transducers.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 1 - Water Circulation in the Coomera River Estuary
    • Abstract: Mirfenderesk, H; Tomlinson, R; Hughes, L This paper describes development of a numerical tidal model and a data collection program for the Coomera River estuary on the Gold Coast. The primary objective of this project was to provide a detailed picture of the tidal characteristics within the study area; to investigate the degree and importance of tidal asymmetry at the Coomera River; to calculate the tidal prism; and also to enable the simulation of water circulation within the study area. A comprehensive data set was collected as part of this study to understand the local dynamics, and to calibrate and validate the model. The collected data include current, water level and meteorological forces in the study area. Calibration and validation were achieved through: comparison of computed tidal harmonics against those derived from harmonic analyses of the measured water level variations; and comparison between the measured discharges across four cross-sections at critical locations within the study area with the discharges predicted through modelling. As part of this study, harmonic analyses of the collected data were conducted to identify the major tidal constituents of the tidal signal within the study area. Calculations show that tide becomes mixed, and is mainly semi-diurnal in the estuary.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 1 - RELWNET: Reliability Evaluation Model for Water
           Distribution Networks
    • Abstract: Moneim, MA; Moawad, AK; El-Molla, A; ElSalawy, MA A reliability model RELWNET has been developed to evaluate the reliability of water distribution networks based on the load-resistance concept. RELWNET is a probabilistic model that applies the generic expectation functions developed by Tyagi and Haan (2001). The probability distributions for load and resistance have been estimated by randomly generating the input variables for the hydraulic capacity of pipes and nodal demands equations using the built-in random functions in MATLAB. The failure probability distribution of the whole system has been determined by applying the k{th} order of moments developed by Haan (1977) to the load-resistance reliability equation. The model RELWNET is coded in MATLAB and is linked to the hydraulic model EPANET2 (Rossman, 1993) to define the risk components by applying pipe closure combination based on the minimum cut-sets. The validation of the model is demonstrated using an example water network reported by Su et al (1987). It is concluded the model RELWNET has proven its ability to complete a reliability evaluation for a small example water distribution network.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 1 - Australians' Water Conservation Behaviours and
           Attitudes
    • Abstract: Dolnicar, S; Hurlimann, A The Australian water crisis can be addressed in many ways, ranging from increasing water conservation behaviours to minimise demand, through to producing water through large-scale water augmentation projects. Due to the extended drought experienced in many locations across Australia in recent years, there has been a recent focus on developing wastewater recycling and seawater desalination plants. While this is an important measure for emergency water supply, water conservation should still play a major role in reducing demand for water. The aim of this study is to provide much-needed empirical data about Australian attitudes towards water conservation and their water conservation behaviours. This market insight provides a knowledge basis for the development of public policy measures and social marketing campaigns aimed at increasing water conservation among Australian residents. Results from a survey study of 1495 people indicates that Australians generally have very positive attitudes towards water conservation and water saving appliances, however, these positive attitudes are not consistently translated into actual behaviour. The main barriers to adoption of water conservation behaviours identified in the study are the perception of inconvenience and impracticality, as well as costs associated with purchasing water saving appliances. These findings highlight the fact that there is still substantial potential to be harvested in Australia though water conservation measures. Opportunities for public policy makers to stimulate this process are identified.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 1 - Streamflow Data Preparation for Regional Flood
           Frequency Analysis: Lessons from Southeast Australia
    • Abstract: Haddad, K; Rahman, A; Weinmann, PE; Kuczera, G; Ball, J This paper presents a case study on streamflow data preparation for a regional flood frequency analysis (RFFA) project for the states of Victoria and NSW, in connection with the forthcoming edition of Australian Rainfall and Runoff. The study gathered annual maximum flood series data for a large number of stations from Victoria and NSW, and applied various statistical techniques to prepare the final data set. It was found that a large primary data set, even if selected using a fairly stringent set of criteria, cannot guarantee a similarly large final data set, as streamflow data are affected by many sources of uncertainty. The trade-offs between quality and quantity are discussed and illustrated. The maximum rating ratio, defined as the ratio of the largest estimated flow and the maximum measured flow at a gauging station, is used to identify stations whose quantiles may be seriously affected by rating curve errors. In a case study involving Victorian stations, the importance of maintaining a high spatial coverage of stations was demonstrated. It was shown that a 50% reduction in the number of stations used in a RFFA resulted in an increase of the standard error of prediction of flood quantiles up to 90%.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 14 Issue 1 - Preface
    • PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 13 Issue 1 - Local Groundwater Management Studies in Ontario,
           Canada: A Case for Retaining a Role for the State in Community-based Water
           Research
    • Abstract: Taylor, Brent; de Loe, Rob; Kreutzwiser, Reid; Bjornlund, Henning Between 1998 and 2003, the provincial government in Ontario, Canada, administered a funding program to support groundwater management studies by local communities. The community focus of the initiative in many ways represents a more collaborative approach to generating the knowledge needed to inform local resource management decisions. The process and outcomes of the study program are assessed based on follow-up interviews with local study participants. We conclude that although the benefits of community-based research are apparent in many of the local study areas (eg. incorporation of local knowledge and values, and heightened community awareness of the need for groundwater protection), a lack of coordination among individual studies has resulted in the production of groundwater information that is incompatible across adjacent study areas and inadequate to support management measures at broader scales (eg. watershed). This outcome suggests the need for greater coordination within community-based water research initiatives where the results and subsequent management actions have potential implications beyond the immediate study boundaries. Thus, our analysis confirms a fundamental challenge of community-based research initiatives, and of decentralised governance approaches more generally - balancing the need for regional uniformity with the desire for greater local autonomy. Strategies for more effectively coordinating communitybased water research are considered. While the analysis focuses on groundwater management and experiences in Ontario, the lessons learned are more broadly transferable.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 13 Issue 1 - On the Physical Modelling of Large Vortex Drop
           Structures in Municipal Sewerage Systems
    • Abstract: Keller, Robert J Classically, dimensional analysis is used to establish the fundamental scaling laws to predict prototype behaviour from observed model results. However, the same dimensional analysis demonstrates that it is not possible to avoid scale effects if the prototype fluid - normally water - is used in the model studies. Flow through hydraulic structures is typically gravitydriven, and equality of Froude Numbers at homologous points in model and prototype leads to the determination of fundamental scaling laws. However, it is well known that, as a consequence, homologous values of other non-dimensional parameters, such as Reynolds Number and Weber Number, are not equivalent and this leads to scale effects due to the imperfect replication in the model of (for example) friction and surface tension effects. In such cases, it is necessary to use process functions to determine the magnitude of the scale effects and to inform the adjustment of measured flow properties in the model to reflect the true value of the flow properties in the prototype. The present paper extends the use of process functions to annular flows, such as those that occur in vortex drop structures and plunge pools. Within the vortex drop, it is shown that the process functions cannot be used to evaluate scale effects directly, but, instead, must be used in conjunction with the model data to develop an analytical model for the prediction of corresponding prototype behaviour. Within the plunge pool, it is hypothesised that the momentum flux at the exit of the vortex pipe must be correctly modelled to ensure the proper replication of flow conditions within the plunge pool. The techniques are developed, and their use illustrated through application to a large physical model study of a vortex drop and plunge pool in a municipal sewerage system. It is shown, further, that ignoring the insight gained from the developed process functions would lead to large errors in the prediction of prototype flow behaviour from measured model results.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 13 Issue 1 - Verification of a Numerical Model for the Prediction
           of Low Slope Vertical Slot Fishway Hydraulics
    • Abstract: Barton, Andrew F; Keller, Robert J; Katopodis, Christos A numerical model has been developed to predict the three-dimensional flow character within low slope vertical slot fishways (VSFs). The model solves the three dimensional Reynolds averaged Navier-Stokes equations, closed with the renormalised k-ε turbulence formulations. The model employs the volume of fluid method to deal with the free surface. Results are presented for velocities and surface elevations utilising two fishway designs from prototype and laboratory studies. The respective data from these studies are directly compared to the numerical model predictions forming the basis of verification. The model is shown to predict critical design velocities, slot flow characteristics, flow recirculation and water surface elevations well enough to be useful in low slope VSF design.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 13 Issue 1 - A Statistical Model for Flood Forecasting
    • Abstract: Zhao, JunHua; Dong, ZhaoYang; Zhao, MuLin A statistical model is proposed in this paper that can be used for river stage forecasting. This model is able to handle the volatilities associated with the data used in flood forecasting. Different from conventional flood forecasting methods, this model works well with fatter-tail distribution and volatility clustering in the flood related data. Observed water stage data from Guangxi, China, are employed to test the proposed method with promising results.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 13 Issue 1 - Multi-year Streamflow Drought in Eastern Australia
    • Abstract: Boughton, Walter C Streamflow drought characteristics were calculated for 123 coastal and inland catchments in eastern Australia. The characteristics for each catchment were determined by stochastic generation of 2000 years of daily rainfalls, which were converted to streamflows using the AWBM rainfall-runoff model. Droughts were calculated from the 2000 years of generated streamflow for durations of 1, 2, 3, 5 and 10 years, and expressed as a percentage of mean annual flow to facilitate comparisons among the catchments. There were six river basins with five or more catchments in the basin - three coastal basins in northern New South Wales and three inland basins in the Murray-Darling drainage division. These showed more variation within each basin than between basins. A long sequence of 100,000 years of streamflow was generated on one catchment, which showed that the severity of droughts increased with average recurrence interval to the limit of the generated data. There was no evidence of any regional influence on or geographical pattern of drought severity. The main result was the large variability of drought severity from catchment to catchment even within river basins.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 13 Issue 1 - Climatic Drivers of Victorian Streamflow: Is ENSO the
           Dominant Influence'
    • Abstract: Keim, Anthony S; Verdon-Kidd, Danielle C This study investigates the relationship between Victorian streamflow and a number of large-scale climate drivers, including the El Nino/Southern Oscillation (ENSO), the Interdecadal Pacific Oscillation (IPO), the Indian Ocean Dipole (IOD) and the Southern Annular Mode (SAM). It is found that identifying a "dominant" climate driver, at least in the case of Victorian streamflow, is not a clear cut exercise. Importantly, it is shown that ENSO alone explains only a very small proportion of Victorian streamflow variability, particularly in autumn (a critical time in Victoria's hydrological and water resources management cycle). This is a crucial insight given that most seasonal forecasting schemes currently used in Australia are based primarily on ENSO relationships. The results presented here show that stratification of Victorian streamflow according to multiple largescale climate drivers, and antecedent catchment conditions, provides significantly differing streamflow distributions. Therefore, incorporation of (a) antecedent catchment conditions into the forecasting framework and (b) improved insights into the multiple interactions between all relevant large-scale (and local) climate drivers should improve seasonal streamflow forecasting ability.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 13 Issue 1 - Comparison of Statistical Downscaling Techniques for
           Multisite Daily Rainfall Conditioned on Atmospheric Variables for the
           Sydney Region
    • Abstract: Mehrotra, Rajeshwar; Sharma, Ashish; Srikanthan, Sri; Frost, Andrew J Predictions of rainfall spatial and temporal variability (including climate change effects) on a catchment basis are urgently required by water resource planners within Australia. Large spatial scale predictions of (typically 300 to 500 km grids) global scale climate scenarios output by General Circulation Models (GCMs) are inadequate for such use as they do not capture the large degree of spatial variability over smaller distances, which is inherent in rainfall. Multisite daily rainfall - a common requirement within many hydrological models - is a required input for modelling complex multi-catchment systems, as small scale spatial variability due to factors such as topography has a large bearing on how much rainfall falls in a given area. Statistical downscaling is a technique that can produce such fine spatial scale rainfall pattern predictions conditional on the larger scale climate scenarios output by a GCM. The GLIMCLIM (Generalised Linear Model for daily Climate time series) software package (Chandler, 2002) has been used to analyse and simulate spatial daily rainfall given natural climate variability influences in the UK, and further to predict the influence of various future climate scenarios on regional rainfall by downscaling larger spatial scale GCM simulations. This paper describes the comparison of this method to the non-parametric, non-homogeneous hidden Markov model - kernel probability density estimation (NNHMM-KDE) downscaling technique of Mehrotra and Sharma (2006), a method which has found application in Australia previously.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 3 - Adjusting Hypothetical Reservoir Storage Estimates for
           Real World Conditions
    • Abstract: McMahon, Tom A This technical note describes the data and analysis to determine a factor to adjust theoretical estimates of reservoir storage capacity, based only on annual inflow hydrology, for practical issues including net evaporation loss, varying operating rules and seasonal demands, monthly inflow variability, dead storage, and site characteristics. Based on an analysis of 30 large Australian reservoirs, a mean adjustment factor between the theoretical storage estimates and the equivalent constructed values was found to be 0.32 ( 0.15).
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 3 - A Case Study of the Improvements Gained in Conduit
           Efficiency by Cleaning a Biofouled Pipeline
    • Abstract: Barton, Andrew F; Wallis, Michael R; Sargison, Jane E; Walker, Gerg J The hydraulic performance of pipelines can be significantly affected by the presence of biological growth on internal surfaces. The change in wall roughness brought about by biofilms has been studied by the use of headloss tests, pre- and post-cleaning, of a low pressure hilltop pipeline of a Hydro Tasmanian hydroelectric scheme. Results of the headloss tests show that improvements to hydraulic efficiency can be achieved from the cleaning of biofouling material, and that identifying the flow velocities at which hydraulically smooth, transitional or rough conditions occur can aid in optimising the operating characteristics of the conduit. Results show both reductions in headloss and improvements in power output at the powerstation at given flow rates. The data when plotted in the style of a Moody diagram shows that the friction law, roughened by biological growth, is observed to deviate from the Colebrook-White relationship, although the results are too narrow in Reynolds number to be conclusive. It was found that bacteria made up the majority of the biofilm biomass in the pipeline studied. Based on molecular analysis, members of the class Alphaproteobacteria were the most frequently detected followed by members of the phylum Chloroflexi. Chemical analyses found high levels of iron, manganese and aluminium in the biofilm.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 3 - Velocity Index Factor Sensitivity to Velocity
           Distribution
    • Abstract: McDermott, Glenn Open channel flow monitoring is moving towards velocity as well as depth sensing to calculate discharge by the continuity method. Such technology always requires an index factor to calculate mean velocity from sensed velocity, because the sensing zone never covers the entire cross section. A new velocity pattern definition model is developed in this paper, based on available hydrographic data for vertical and horizontal velocity distributions. This model is used to study the sensitivity of the velocity index factor to channel shape, depth of flow, velocity pattern asymmetry and type of sensor. The results demonstrate that this factor value should not be assumed constant and can vary by more than 30%.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 2 - Optimisation of Mains Trickle Top-up Volumes and Rates
           Supplying Rainwater Tanks in the Australian Urban Setting
    • Abstract: Barry, Michael E; Coombes, Peter J The use of roof collected rainwater stored in tanks as a supplement to traditional domestic urban water supply systems is becoming increasingly common in Australia, especially given growing environmental awareness and ongoing drought conditions. Rainwater tanks must be appropriately configured in order to effectively meet demand. Two aspects of this configuration are the preset mains trickle top-up rate and trickle top-up volume, where such devices are installed. Improper configuration of these parameters may result in ongoing tank failure in such systems. As such, there is a need to improve our understanding of how these parameters influence tank performance in various rainfall climates around Australia. Following from previously published studies, this paper reports ongoing investigations undertaken to address this need. For a range of top-up volumes and rates, it is shown that tank performance is highly dependent on demand, and comparatively weakly dependent on tank size. Seasonal variations in tank failure are investigated and correlated with rainfall and yield patterns, in the context of top-up rate and volume configurations. Failure and yield surfaces are presented for a range of occupancies, and are discussed in relation to optimal rainwater tank design.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 2 - The Impact of End-use Dynamics on Urban Water System
           Design Criteria
    • Abstract: Thyer, Mark; Hardy, Matthew; Coombes, Peter; Patterson, Clinton The potential impact of demand reduction strategies (reuse/source substitution via tanks/installing water efficient appliances) on urban water system design criteria (average/peak demands and wastewater flows) was investigated using two months of detailed end-use monitoring from a single house. Reductions in regular water use events (shower/toilet) had a larger impact on average demand/flows, while reductions in sporadic water use events (outdoor/washing machine) had a larger impact on peak demands/flows. Highest predicted reductions of 71%/83% in average/ peak demand occurred when using a 5 kL tank to supply toilet, washing machine (5-star), outdoor and hot water use. Further research is needed to quantify these impacts on a larger scale. Given the potential for reductions in urban water infrastructure costs this research is considered a high priority.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 2 - Stormwater Harvesting: Assessing Operational System
           Performance
    • Abstract: Burns, Matthew J; Mitchell, Grace V Recently, it has become apparent that stormwater harvesting has the potential to play a significant role in the sustainable management of water resources. However, it has been recognised that uncertainties concerning the operational performance of existing stormwater harvesting systems and also the lack of appropriate design standards are barriers to the widespread adoption and utilisation of stormwater harvesting. In this study, we gathered design and operational information regarding three stormwater harvesting systems located in Melbourne, as well as undertaking water quality and quantity monitoring. It was found that the design objectives of each system were developed in order to meet a range of environmental, social and economic outcomes, and while most of these objectives were met, some were rather qualitative and so were difficult to assess. The design of each harvesting system did not represent what was built and this is likely to be limiting operational performance. The ongoing drought has severely impacted on the volume of stormwater harvested from the two smaller systems, however, recent winter/spring rainfall has increased the volume of stormwater in storage. In comparison, the larger system has been able to provide signifi cant amounts of stormwater during the very dry summer of 2007 and throughout the year. Preliminary water quality monitoring indicated that systems featuring WSUD devices are able to improve the water quality (in terms of TSS, TN and TP) of stormwater. Importantly, it appears that systems that do not have disinfection will more frequently have E. coli levels that exceed 10 orgs/100 mL.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 2 - Paired Catchment Storm Event Monitoring: Assessing the
           Performance of a Bioretention System (Rain Garden)
    • Abstract: Lloyd, Sara; Wong, Tony Treating urban runoff at its source offers to protect receiving waters by modifying flow characteristics and improving water quality. This paper presents the findings for a paired catchment storm event monitoring program undertaken at a residential development, the Lynbrook Estate, Victoria, Australia. The monitoring program compares catchment runoff characteristics between a landscaped bioretention system and a conventional concrete pipe system located in adjacent urbanised subcatchments. Results indicate that the extent to which bioretention systems function as hydrological buffers depends on their design attributes, in-situ geology, antecedent moisture conditions at inflow and storm magnitude. Reductions in total runoff volume, duration and peak flows discharged from the bioretention system compared to the piped system were observed. Small, frequently-occurring runoff events are completely retained by the system. Pollutant loads are reduced by a combination of catchment runoff retention and physical and/or chemical treatment processes, with the former being the dominant process for nutrients and the latter being dominant for suspended solids. Analysis of pollutant load reduction for the 10 events showed gross pollutant load was reduced by 100%, suspended sediment by 68%, total phosphorus by 60% and total nitrogen by 57%.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
  • Volume 12 Issue 2 - Improving Stream Low Flow Regimes in Urbanized
           Catchments Using Water Sensitive Urban Design Techniques
    • Abstract: Lee, Ahrim; Hewa, Guna; Pezzaniti, David; Argue, John R As a catchment becomes urbanised, the natural hydrological processes are significantly altered and this leads to a deterioration of the stream's ecological condition. Low flow characteristics of a stream are useful hydrological statistical indicators for assessing the health of an ecosystem. An investigation was carried out to assess the capacity for water sensitive urban design (WSUD) measures to maintain "natural" low flow characteristics when a catchment is urbanised. A calibrated Storm Water Management Model (SWMM) of a natural catchment in South Australia was developed using historical rainfall and stream flow data. Prior to the model calibration, the sensitivity of the SWMM parameters was assessed against hydrological responses on the low flow region of the flow duration curves (FDCs) and the deficit volumes at three selected threshold flows over the calibration period. The calibrated model was then modified to generate flow data for three selected urbanised scenarios by altering the percentage of effective impervious areas. Model resolution effects on low flow regimes were assessed to ensure spatially distributed effects did not influence the results. Two selected WSUD measures were applied to one of the urbanised scenarios and low flow characteristics were examined. Flow duration and spell duration-frequency statistics of the urbanised cases were compared against those of the natural catchment. The study revealed that urbanisation causes more frequent low flow spells during both the wet and the dry seasons. As expected, the frequencies of the low flow spells with duration up to 20 days increased dramatically due to urbanisation. Both WSUD measures were capable of achieving similar frequencies for the same "natural" spell durations. The frequency of low flow spell duration events was reduced as WSUD measures were applied to the urbanised catchment case, indicating that the low flows with WSUD measures will generally be higher than those without WSUD. For the case study catchment, WSUD infiltration measures that are capable of diverting up to half of the natural groundwater input will enable low flow characteristics to be maintained.
      PubDate: Tue, 19 Jun 2012 12:27:38 GMT
       
 
 
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