 Subjects -> WATER RESOURCES (Total: 160 journals)
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- The impact of water conservation policies on the reallocation of
agricultural water-land resources
Authors: Hadis Kavand, Saman Ziaee, Mostafa Mardani Najafabadi
Abstract: The effects of policies on farmers' profit have a key role in their adoption by the farmers and their operationalization at the basin level. The present research explored the effects of water resources conservation policies on optimal cropping pattern and farmers' profit in the Zayanderud basin located Iran using a combined hydrological-economic model composed of WEAP and multi-objective (MOP) models for the assessment of the effects of the A2 climate change scenario with or without the conservation policies. The results showed that climate change will reduce crop yields by 0.5–4%, will decrease water availability by 12–19%, and will increase crop water requirements by 0–4%. It was also found that the adoption of the policy of changing irrigation technology along with the policy of limiting groundwater use will alleviate the effects of climate change on the farmers' profit, will enhance their planned return per unit area by 5%, and will increase the economic efficiency of water use from 5,283 to 6,002 IRR/m3. But, the policy of increasing water price cannot improve the farmers' profit at the basin level and the economic efficiency of water use although it can reduce water use. So, proving the improvement of profit and livelihood of the farmers by applying combined water resources conservation policies can play a significant role in motivating farmers to accept these policies, operationalizing optimal water resources management, and resolving conflicts over water use in this basin.
PubDate: 2023-03-17T00:00:00Z
- Working together: A study of civil society partnerships between WASH
(water, sanitation, and hygiene) and GESI (gender equality and social
inclusion) organisations in Timor-Leste
Authors: Melita Louise Grant, Therese Tam Nguyen, Ajerino Vieira, Sara Louise Niner, Chris Roche
Abstract: This article reports on an empirical study conducted in Timor-Leste that explored the drivers, benefits, and challenges of partnerships and collaborations between water, sanitation, and hygiene (WASH) and gender equality and social inclusion (GESI) organisations as integral parts of the WASH system. The research design was primarily qualitative and included a data-collection workshop with 30 representatives from 16 civil society organisations (CSOs) in Dili, longitudinal research involving two rounds of semi-structured interviews over 2.5 years with five organisations, and semi-structured interviews with an additional 18 CSOs. We applied a framework of post-development theory, including critical localism and working contingently. Key drivers to form partnerships were found to be the identification of community WASH service gaps and the alignment of advocacy agendas. Key benefits reported were increased inclusion and empowerment outcomes and strengthened organisational knowledge and capacity. Challenges emerge when organisations' key staff change, strategies misalign, and financial and administrative capabilities differ. The study contributes practical insights into how civil society organisations (CSOs) partner to strengthen mutual WASH and GESI strategies and programmes and their outcomes. We recommend strengthening the partnerships between WASH and GESI organisations in ways that are cognisant of power dynamics, local priorities, and capacity needs and promote longevity and continuity through ownership of decisions at the local level. Our findings suggest that meaningful, reciprocal, and respectful engagement with WASH and GESI organisations enables WASH programmes to be in a better position to address the harmful norms that drive inequitable behaviours, thus strengthening localism, and the WASH governance system overall.
PubDate: 2023-03-16T00:00:00Z
- Advancing water justice through a tribally-driven partnership: Designing
sustainable rainwater harvesting systems in the Yukon–Kuskokwim delta of
Alaska
Authors: Thomas Pool, Mike Williams, Claire McDonald, Patrick Loderhose, Jocine Velasco, Clarita Lefthand-Begay
Abstract: Community driven co-design models can help collaborators to respectfully engage in projects that provide much-needed resources and services to underserved communities. For example, partnerships between tribal, academic, and non-profit collaborators have the potential to generate positive outcomes for communities when individual efforts by those same groups may be less successful. However, cultural and spiritual differences between collaborators (particularly tribal and non-tribal) can lead to misunderstandings and negative project outcomes, despite good intentions and an honest effort by collaborators to achieve a common goal. Here, we provide a case study of a community-driven co-design project involving tribal, academic, and private collaborators to design and build a rainwater harvesting system with the Akiak Native Community (ANC), and their tribal council in Alaska, USA. A novel collaborative co-design process honoring the tribal sovereignty of the ANC is emphasized in this case study; a design model that is poorly represented in the literature with real-world examples. Logistics associated with designing and constructing the community-use rainwater harvesting system on Alaskan tribal lands is reviewed but the focus of this work is on the collaborative design process more so than the construction of the water harvesting system end product. More explicitly, the use of multiple approaches to promote collaborator involvement along with an emphasis on developing community driven project goals are highlighted as essential steps in our co-design process.
PubDate: 2023-03-15T00:00:00Z
- Investigation of hydrometeorological influences on reservoir releases
using explainable machine learning methods
Authors: Ming Fan, Lujun Zhang, Siyan Liu, Tiantian Yang, Dan Lu
Abstract: Long short-term memory (LSTM) networks have demonstrated successful applications in accurately and efficiently predicting reservoir releases from hydrometeorological drivers including reservoir storage, inflow, precipitation, and temperature. However, due to its black-box nature and lack of process-based implementation, we are unsure whether LSTM makes good predictions for the right reasons. In this work, we use an explainable machine learning (ML) method, called SHapley Additive exPlanations (SHAP), to evaluate the variable importance and variable-wise temporal importance in the LSTM model prediction. In application to 30 reservoirs over the Upper Colorado River Basin, United States, we show that LSTM can accurately predict the reservoir releases with NSE ≥ 0.69 for all the considered reservoirs despite of their diverse storage sizes, functionality, elevations, etc. Additionally, SHAP indicates that storage and inflow are more influential than precipitation and temperature. Moreover, the storage and inflow show a relatively long-term influence on the release up to 7 days and this influence decreases as the lag time increases for most reservoirs. These findings from SHAP are consistent with our physical understanding. However, in a few reservoirs, SHAP gives some temporal importances that are difficult to interpret from a hydrological point of view, probably because of its ignorance of the variable interactions. SHAP is a useful tool for black-box ML model explanations, but the hydrological processes inferred from its results should be interpreted cautiously. More investigations of SHAP and its applications in hydrological modeling is needed and will be pursued in our future study.
PubDate: 2023-03-14T00:00:00Z
- Super-resolution and uncertainty estimation from sparse sensors of
dynamical physical systems
Authors: Adam M. Collins, Peter Rivera-Casillas, Sourav Dutta, Orie M. Cecil, Andrew C. Trautz, Matthew W. Farthing
Abstract: The goal of this study is to leverage emerging machine learning (ML) techniques to develop a framework for the global reconstruction of system variables from potentially scarce and noisy observations and to explore the epistemic uncertainty of these models. This work demonstrates the utility of exploiting the stochasticity of dropout and batch normalization schemes to infer uncertainty estimates of super-resolved field reconstruction from sparse sensor measurements. A Voronoi tessellation strategy is used to obtain a structured-grid representation from sensor observations, thus enabling the use of fully convolutional neural networks (FCNN) for global field estimation. An ensemble-based approach is developed using Monte-Carlo batch normalization (MCBN) and Monte-Carlo dropout (MCD) methods in order to perform approximate Bayesian inference over the neural network parameters, which facilitates the estimation of the epistemic uncertainty of predicted field values. We demonstrate these capabilities through numerical experiments that include sea-surface temperature, soil moisture, and incompressible near-surface flows over a wide range of parameterized flow configurations.
PubDate: 2023-03-14T00:00:00Z
- Disentangling the responses of dissolved organic carbon and nitrogen
concentrations to overlapping drivers in a northeastern United States
forested watershed
Authors: Manya Ruckhaus, Erin C. Seybold, Kristen L. Underwood, Bryn Stewart, Dustin W. Kincaid, James B. Shanley, Li Li, Julia N. Perdrial
Abstract: The concurrent reduction in acid deposition and increase in precipitation impact stream solute dynamics in complex ways that make predictions of future water quality difficult. To understand how changes in acid deposition and precipitation have influenced dissolved organic carbon (DOC) and nitrogen (N) loading to streams, we investigated trends from 1991 to 2018 in stream concentrations (DOC, ~3,800 measurements), dissolved organic nitrogen (DON, ~1,160 measurements), and dissolved inorganic N (DIN, ~2,130 measurements) in a forested watershed in Vermont, USA. Our analysis included concentration-discharge (C-Q) relationships and Seasonal Mann-Kendall tests on long-term, flow-adjusted concentrations. To understand whether hydrologic flushing and changes in acid deposition influenced long-term patterns by liberating DOC and dissolved N from watershed soils, we measured their concentrations in the leachate of 108 topsoil cores of 5 cm diameter that we flushed with solutions simulating high and low acid deposition during four different seasons. Our results indicate that DOC and DON often co-varied in both the long-term stream dataset and the soil core experiment. Additionally, leachate from winter soil cores produced especially high concentrations of all three solutes. This seasonal signal was consistent with C-Q relation showing that organic materials (e.g., DOC and DON), which accumulate during winter, are flushed into streams during spring snowmelt. Acid deposition had opposite effects on DOC and DON compared to DIN in the soil core experiment. Low acid deposition solutions, which mimic present day precipitation, produced the highest DOC and DON leachate concentrations. Conversely, high acid deposition solutions generally produced the highest DIN leachate concentrations. These results are consistent with the increasing trend in stream DOC concentrations and generally decreasing trend in stream DIN we observed in the long-term data. These results suggest that the impact of acid deposition on the liberation of soil carbon (C) and N differed for DOC and DON vs. DIN, and these impacts were reflected in long-term stream chemistry patterns. As watersheds continue to recover from acid deposition, stream C:N ratios will likely continue to increase, with important consequences for stream metabolism and biogeochemical processes.
PubDate: 2023-03-13T00:00:00Z
- A call for strategic water-quality monitoring to advance assessment and
prediction of wildfire impacts on water supplies
Authors: Sheila F. Murphy, Charles N. Alpers, Chauncey W. Anderson, J. Ryan Banta, Johanna M. Blake, Kurt D. Carpenter, Gregory D. Clark, David W. Clow, Laura A. Hempel, Deborah A. Martin, Michael R. Meador, Gregory O. Mendez, Anke B. Mueller-Solger, Marc A. Stewart, Sean E. Payne, Cara L. Peterman, Brian A. Ebel
Abstract: Wildfires pose a risk to water supplies in the western U.S. and many other parts of the world, due to the potential for degradation of water quality. However, a lack of adequate data hinders prediction and assessment of post-wildfire impacts and recovery. The dearth of such data is related to lack of funding for monitoring extreme events and the challenge of measuring the outsized hydrologic and erosive response after wildfire. Assessment and prediction of post-wildfire surface water quality would be strengthened by the strategic monitoring of key parameters, and the selection of sampling locations based on the following criteria: (1) streamgage with pre-wildfire data; (2) ability to install equipment that can measure water quality at high temporal resolution, with a focus on storm sampling; (3) minimum of 10% drainage area burned at moderate to high severity; (4) lack of major water management; (5) high-frequency precipitation; and (6) availability of pre-wildfire water-quality data and (or) water-quality data from a comparable unburned basin. Water-quality data focused on parameters that are critical to human and (or) ecosystem health, relevant to water-treatment processes and drinking-water quality, and (or) inform the role of precipitation and discharge on flow paths and water quality are most useful. We discuss strategic post-wildfire water-quality monitoring and identify opportunities for advancing assessment and prediction. Improved estimates of the magnitude, timing, and duration of post-wildfire effects on water quality would aid the water resources community prepare for and mitigate against impacts to water supplies.
PubDate: 2023-03-13T00:00:00Z
- Environmental isotopes (δ18O–δ2H, 222Rn) and electrical conductivity
in backtracking sources of urban pipe water, monitoring the stability of
water quality and estimating pipe water residence time
Authors: Seifu Kebede, Kidist Hailu, Abdulhafiz Siraj, Behailu Birhanu
Abstract: This study demonstrates the use of environmental tracers (Water isotopes-δ18O–δ2H, Radon-222Rn, and Electrical Conductivity-EC) as complementary tools for backtracking the water source, estimating pipe water residence time, and monitoring the instability of the water quality. Using the capital of Ethiopia, Addis Ababa, as a case study site, we demonstrate that water isotopes (δ18O andδ2H) effectively backtrack the tap water to its source (springs, reservoirs, shallow aquifers, or deep aquifers). 222Rn is shown to be effective for discriminating groundwater-sourced pipe networks from those that are dominated by surface waters. Our reconnaissance survey reveals that 222Rn, a tracer previously not considered to determine the pipe water residence time, can be used effectively to determine pipe water residence time in groundwater-sourced pipe networks. We recommend further research to explore the capability of 222Rn as a robust indicator of the pipe water residence time in an urban piped water network. The tracers reveal that 50% of the city obtains its water from groundwater and that the groundwater-sourced areas of the city show the highest water quality instability. The water quality in groundwater-sourced pipes varies depending on pumping stoppage owing to power interruptions. Surface water-sourced pipe water shows seasonal variations in water quality, with occasional large deviations from the normal trends following flow interruptions.
PubDate: 2023-03-13T00:00:00Z
- A preliminary global hydrochemical comparison of lakes and reservoirs
Authors: Marlene Dordoni, Paolo Zappalà, Johannes A. C. Barth
Abstract: Lakes and reservoirs are important for environmental anthropogenic functions in terms of agriculture and/or settlements. Here we present a first global overview of their chemistry by considering 1,508 water bodies, with data from 485 peer-reviewed publications from 1868 to 2020 and further five online databases. This work focusses on major ions (Ca2+, Mg2+, Na+, K+, HCO3-&CO32-, Cl−, SO42-) and investigates analogies as well as differences between lakes and reservoirs. We applied a Principal Component Analysis (PCA) to group both types of water bodies and to find differences and similarities. The PCA identified fewer variabilities for major ions in reservoirs than in lakes. Moreover, our analyses showed that lakes generally have more total dissolved solids (TDS). Such higher TDS loads in lakes could result from more diverse (and less controlled) inputs from larger catchments and from longer lasting interactions with thicker internal sediment layers. Global median geochemical compositions identified both reservoirs and lakes as calcium-bicarbonate-type waters. This first synthesis provides a basis for future studies and may serve as the start of a global database on these important water bodies.
PubDate: 2023-03-09T00:00:00Z
- The interaction of local people and natural area in Haraz drainage basin;
Case study: Ab-e Ask village
Authors: Mojdeh Rakhshan, Hossein Mahmoudi, Asghar Abdoli, Hadi Veisi, Sima Babrgir
Abstract: According to the importance of Locals impact on conservation, this research had tried to find the role of locals in the protection of natural resources and ecosystems, and also tried to clarify the external laws which are affecting on local's livelihood. This research had done in Ab-e Ask village which is located on the edge of the Lar National Park and along the Haraz River, which is one of the five protected rivers in Iran, and it used the public participatory methods. Using the “Problem Tree,” “Before and After Diagram,” “Social Resources Map,” and etc., helped us to find the answers of: 1. The main reasons of water pollution 2. The land ownership‘s effect on livelihood 3. Finding the traditional approaches of conservation. Finally, the results were about: 1. The sewage of Haraz Road Restaurants and also the pollution of fish ponds were the main water pollution reasons. 2. The effect of Land Ownership Law was clarified and 3. There were two Local Traditions that protect the natural resources, one was called “Barf-e-Chal” which was about saving the water sources for the summer, and the other was about protecting the plants of region until the end of pollination season that results in protecting the flora.
PubDate: 2023-03-01T00:00:00Z
- Projecting hydrologic change under land use and climate scenarios in an
agricultural watershed using agent-based modeling
Authors: David Dziubanski, Kristie J. Franz
Abstract: Watershed systems are changing due to human activities within the landscape and shifting precipitation patterns, and quantifying the coupled effects of these two factors is necessary for anticipating future hydrologic response. In this study, we use a model that combines an agent-based model (ABM) with a semi-distributed hydrologic model to assess how projected changes in precipitation and temperature affect streamflow when simultaneously considering how those variables impact the land use decisions that also influence watershed response. We use a flood-prone watershed which is characteristic of many agriculturally-dominated watersheds in the central Midwest US. In the ABM, farmer agents make decisions that affect land use based on factors related to profits, past land use, neighbor influence, and internal behavior. A city agent aims to reduce urban flooding by paying farmer agents a subsidy for allocating land to conservation practices that reduce runoff. We run the model for the 2018–2097 period using the Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 climate scenarios and different decision-making options. The model reveals that under future precipitation, which becomes increasingly intense leading to more in-field flooding, farmers increase conservation land by up to 60%. This land conversion results in a 4–7% decrease in mean 95th percentile discharge relative to scenarios where conservation land is held constant at the historical mean. If farmers are allowed to modify their internal behavior and preferences, the mean 95th percentile discharge decreases further (up to 16%). Using the assumption that land owners are willing to adapt their personal preferences to mitigate the negative effects of climate change on their land and external incentives exist to do so, upstream runoff mitigation practices could reduce downstream impacts from more frequent intense precipitation. However, farmer agents converted, on average,
PubDate: 2023-02-24T00:00:00Z
- Disrupted water governance in the shadows: Revealing the role of hidden
actors in the Upper Cauca River Basin in Colombia
Authors: Alejandro Figueroa-Benitez, Mohsen Nagheeby, Apolinar Figueroa, Jaime Amezaga
Abstract: Colombia's policy in the Upper Cauca River Basin is diminished by a lack of legitimacy in local areas respecting the control of territory and water. Such illegitimate interference provides a hiding place and fertile ground for the illegal activities of “hidden” actors. This paper aims to scrutinize the potential power of such hidden actors to influence water governance. We engage with critical discussions of water governance to reveal the role of these actors in controlling territory and water in the Upper Cauca River Basin. Extensive fieldwork was carried out, including workshops, interviews, and informal talks. Despite the Colombian government not recognizing hidden actors and their part in influencing water-related policies, the information gathered revealed their active agency in the basin. The paper shows how these actors play a determining role in territorial development and water resource management, disrupting the functioning of the State's water governance. Hidden actors, to promote their own, mostly illegal and illegitimate businesses, seize upon the current lack of clarity in the national normative standards, the deficiencies created by an inconsiderate implementation of national water policy, and the State's lack of legitimacy at the local level. This paper concludes that the awareness of hidden actors and their invisible power over water governance provide a better sense of the reality on the ground for policymakers in Colombia.
PubDate: 2023-02-24T00:00:00Z
- Implementing a participatory model of place-based stewardship for
inclusive wetland management: A community case study
Authors: Jessica M. Reeves, Patrick R. Bonney
Abstract: The inclusion of local values and an appreciation for different ways of knowing are increasingly considered core principles in wetland management but can be difficult to achieve in practice. This Community Case Study describes the development and impacts of a participatory action research (PAR) project focused on the creation of a community-led stewardship and knowledge sharing in a rural coastal community in Victoria, Australia. The project, Living Bung Yarnda, was designed around four dimensions: vision, knowledge, narrative, and capacity—that align with key principles of PAR and guided the process of knowledge building and exchange. Working with a range of stakeholders, including environmentally-focussed community members, government agencies and Traditional Owners groups, we aimed to discover pathways for the inclusion of local knowledge, lived experience, and acts of care by community members in governance processes. The case description illustrates how embedded knowledge in this community is currently undervalued by management agencies but, if harnessed, can contribute to more holistic and equitable forms of wetland management. We conclude with reflections on the development of the project, emphasizing the role of academic researchers in fostering relationships between community and management authorities that is built on trust, humility and a willingness to find a common language.
PubDate: 2023-02-23T00:00:00Z
- Nitrogen removal performance and bacterial community analysis of a
multistage step-feeding tidal flow constructed wetland
Authors: Mishari Khajah, Franciszek Bydalek, Akintunde O. Babatunde, Abdullah Al-Matouq, Jannis Wenk, Gordon Webster
Abstract: A multistage mesocosm vertical flow constructed wetland system was designed to treat synthetic domestic wastewater with a high nitrogen (N) load. The study aim was to determine the impact of design and operational variables on N removal efficiency in such systems. A tidal flow operational strategy enhanced aeration and was coupled with a step-feeding approach to promote N removal. Over the 420-day running period N removal rates were between 70 and 77 gN/m3/d, for a step-feeding ratio range of 60:40 to 80:20. The system was able to remove 91–95% of chemical oxygen demand, 74–91% of ammonium and 66–81% of total-N. Tidal flow and step-feeding strategies significantly impacted nitrogen removal with the best performance at a step-feeding ratio of 80:20 providing a carbon to nitrogen (COD/N) ratio of 4–5. The bacterial diversity increased at each stage throughout the system with dominating phyla Proteobacteria, Firmicutes, Planctomycetes, Bacteroidetes, Chloroflexi, Verrucomicrobia and Acidobacteria. Dominant bacteria at the genus level were Thiothrix, Planctomyces, Azonexus, Pseudoxanthomonas, Hydrogenophaga, Gemmobacter and other genera suggesting that N removal was accomplished via diverse metabolic pathways, including autotrophic nitrification, heterotrophic denitrification, autotrophic denitrification, and possibly anammox. This study shows benefits of step-feeding strategies in tidal flow constructed wetlands as a cost-effective solution for minimizing external carbon input to achieve effective N removal.
PubDate: 2023-02-23T00:00:00Z
- Reifying “river”: Unpacking pluriversal possibilities in rejuvenation
surrounding the Adi Ganga of Kolkata
Authors: Shreyashi Bhattacharya, Jenia Mukherjee, Anuradha Choudry, Raktima Ghosh
Abstract: Using the River Adi Ganga as the case study and implementing the historical urban political ecology (HUPE) framework, in this article we demonstrate multiple trends and trajectories that comprise city-river relationships. We explore coeval ontologies framing “river,” “riverine space” and “river rejuvenation” schemes, encapsulating “storylines” through the deployment of multi-modal (qualitative) research methodologies to trace and document plural perceptions on the river that was declared to be “dead”—the pillaged stretch that embodied the construction of the metro pillars. Media journalists and activists' narrative, that this act had slaughtered the river and robbed her of her original flows and services, has crafted a deep imprint on the citizens of Kolkata who consider the river as a stinking sink, offering minimal sewerage facilities to the city. Our paper challenges this linear depiction and weaves together positive moments, events and actions that keep the river flowing—shaping and in turn being shaped by (more-than)human actors across long temporal units and scales. We integrate the numerous agential and stakeholder voices attached to the river, shedding light on various (un)successful attempts to revive the river beyond global conceptualizations of what a “river” should be. We believe that the unfolding of this “pluriverse” will forge sustainable understandings of the river's current challenges and existing opportunities toward a collaborative blueprint through knowledge coproduction, stakeholder mobilization and actions. While our empirical frame of reference focuses on micro-realities surrounding a particular river on a specific urban hydroscape, our theoretical conceptualization framings and methodological applications will have potentials to be implemented at scales.
PubDate: 2023-02-21T00:00:00Z
- Editorial: Emerging trends on adaptive capacity and water security
measures under a looming climate change threat
Authors: Olusola O. Ololade, Bethany O'Shea, Amy Quandt, Vishnu Pandey, Saheed Oke
PubDate: 2023-02-20T00:00:00Z
- Review: Groundwater research in the Ethiopian Rift Valley Lakes region
Authors: Taye Alemayehu Hulluka, Sisay Kebede Balcha, Biniyam Yohannes, Amare Bantider, Adey Negatu
Abstract: Despite its proximity to many research institutions in the country and prevailing environmental and water security challenges, water resources research in the Central Rift Valley of Ethiopia has few decades of history. Research undertaken so far, mainly focus on the lakes' environment and anthropogenic activities in their proximities. Worsening deterioration of the water resources and environmental conditions; and the need to address overlooked but determinant natural and anthropogenic processes spurred a critical review of what has been done so far. This work provides an overview of the history of water research in the central rift valley and tries to reveal research gaps related to surface water-groundwater interaction, water quality, and changing trends in the hydro ecosystem and possible causes. Apart from this, articles dealing with the geological and structural setup of the central rift valley were systematically reviewed to show their control over the hydrologic system. The review work has revealed that although the current state of the central rift valley is a product of anthropogenic and geogenic processes; which are happening within the sub-basin and its adjacent basins that need to be addressed at a higher thematic, spatial, and temporal scopes, there is gap in reviewed research, to address the issue at this level. The forefront environmental challenges and the need for quick fixes, lack of data, and funding are found to be some of the reasons to limit the scope of research activities, mainly to shallow groundwater zones and surface hydrological processes around the lakes. This approach has hindered seeing the bigger picture and resulted in ineffective environmental and natural resources restoration measures and policy decisions.
PubDate: 2023-02-16T00:00:00Z
- Editorial: Hydrosphere-cryosphere interactions in the Himalayas under
climate change
Authors: Riyaz Ahmad Mir, Farooq Ahmad Dar, Khalid Muzamil Gani
PubDate: 2023-02-16T00:00:00Z
- Insects in water towers: Hibernating flies could compromise microbial
drinking water quality
Authors: Amber Baele, Fien Waegenaar, Katrien De Maeyer, Bart De Gusseme, Han Vervaeren, Pieter Spanoghe, Nico Boon
Abstract: Providing safe and qualitative drinking water is becoming increasingly important due to climate change and population growth. Water towers are often used to provide storage and ensure water pressure for drinking water distribution. However, microbial regrowth of water is still a challenge during storage and distribution. Moreover, water towers can be used as an aggregation site by insects, mainly flies (Diptera). In this study, ten water towers in Belgium were monitored for 8 months with sticky traps to evaluate fly species diversity, abundances and activity. The results showed the presence of three fly species: Thaumatomyia notata (yellow swarming fly), Musca autumnalis (face fly) and Pollenia spp. (cluster fly). The flies entered the towers in autumn and took shelter against wintering conditions in cracks and crevices, especially on the highest floors where the water tank is located. In this way, flies can come into contact with the drinking water. Based on the monitoring campaign, a risk assessment matrix was set up to determine risks of possible microbial water contaminations caused by flies in water towers. This was validated by a worst-case experiment in laboratory conditions. Face flies (living and dead) were added to tap water to evaluate their influence on microbial water quality and safety using several techniques such as 16S rRNA amplicon sequencing, flow cytometric cell counts and fingerprinting. Our research showed that flies in drinking water promote bacterial growth and change the phenotypic resident drinking water community. Furthermore, new genera such as Pseudomonas and Acinetobacter as well as the coliforms Serratia fonticola and S. liquefaciens were detected when flies were added to tap water. Hence, prevention and intervention measures are important in water quality management to avoid contact between flies and drinking water in water towers. In this study, several effective prevention methods are discussed, such as sealing ventilation, overflow and weep holes with insect screens with adequate mesh size and covering water tanks.
PubDate: 2023-02-14T00:00:00Z
- Overcoming Resource Nexus Conflicts With a Normative-Institutional
Approach: A Case Study of Brazil
Authors: Priscila Carvalho, Catalina Spataru
Abstract: Water-energy nexus research highlights the need for co-management across water and energy sectors, whereby joint planning and solutions under better integrated governance of resources could make action more efficient and cost-effective to advance the SDGs. A gap remains in the literature with regards to the normative dimension of the resource nexus. At the background or resource nexus conflicts there are norms, which need to be considered and applied in the resolution of disputes. Brazil has been chosen as case study because of rising conflicts around its high dependency on water and hydropower generation to keep affordable tariffs, while securing multiple water uses. Hydrological factors (e.g., prolonged droughts) and non-hydrological factors (e.g., chronic delays in delivery of new plants and transmission lines) have impacted on water availability, which led to constraints for hydropower generation, with cascading economic, social and environmental impacts. Electricity prices have risen, while water quantity and quality have decreased, affecting multiple users and ecological integrity of rivers. All of which impact negatively on livelihoods and water services and sanitation, aggravated by the fact that electricity represents one of the fastest growing costs for Water services, Sanitation and Hygiene (WASH) suppliers. The novel combination of research methods based on metrics, historical-institutional analysis, questionnaire, and in-depth interviews served as instruments for the assessment of the water-electricity nexus issues and development of a new legal approach to manage conflicts arising in Brazil. Most of the existing work has favored integration of water and electricity sectors based on quantitative approach to address the interlinkages between them and tackle trade-offs. However, from a legal perspective, very little is known about how these sectors could be better integrated in practice. This study proposes a normative-institutional approach that offers a flexible, integrated, and adequate legal treatment to overcome the conflicts between water and electricity in the context of their asymmetrical governance, policies, regulation, planning and environmental injustices. Split in substantive, institutional, and procedural dimensions this approach is necessary to enhance participatory and equitable resource governance based on the laws of balancing legal principles, rational, inclusive, and transparent procedures. It was concluded that for water-electricity nexus thinking to be connected to the idea of integration it will be necessary to consider justice by taking a normative-institutional approach that can support advances to the SDGs in more holistic and fair ways.
PubDate: 2023-02-10T00:00:00Z
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