Authors:B Nanaa, O Sanogob, PW Savadogoa, T Dahoa, M Boudad, J Koulidiatia Abstract: In this work, a study on air quality in the city of Ouagadougou (Burkina Faso) was carried out. The concentration levels of NO2, SO2, BTEX and PM10 in the city have been quantified. The results show that NO2 concentrations (range from 22 to 27 μg m-3 on average) in the city remain below the limit set by the WHO standard, except for downtown where values often exceed this standard. The average concentrations of SO2 (range from 0.5 to 10.5 μg m-3) remain low in general throughout the city. The concentrations of BTEX (e.g. benzene: 27.9 μg m-3) are high in the city. PM10 concentrations are very high in the city in general; they exceed the limit set by the WHO standard by a factor of 3 to 4. These PM10 are mostly composed of dust from the desert and the re-suspension of dust particles related to vehicles traffic on unpaved roads. Two daily peaks for PM10 are observed at heavy traffic hours. Finally, the study showed that the values of PM10 concentrations observed are in the same order of magnitude of those generally observed in the Sahelian region (range from 119 to 227μg m-3). Issue No:Vol. 7, No. 1
Authors:PC Nwilo, DN Olayinka, J Obiefuna, AO Atagbaza, AE Adzandeh Abstract: Temperature is an important component of the climate. The temperature of a developing city or state is constantly changing. The trend in temperature change in Nigeria is not consistent. Changes in temperature appear to be closely related to concentrations of atmospheric carbon dioxide. The degree of concentration depends on human interventions and the amount of sunlight reaching the earth's surface. Lagos State particularly in recent time has experienced decrease in vegetation and water pervious surfaces, which reduces surface temperature through evapotranspiration. This is as a result of rapid urbanization arising from inundating rural-urban migration. One of the implications is that anthropogenic heat is released to the environment due to energy consumption and increased impervious surface coverage thereby increasing the surface and atmospheric temperatures. LandSat Satellite imageries have been used to estimate Land Surface Temperature (LST) and urban thermal conditions. The mean LST result shows that, there is a significant increase in the temperature values from 1984 to 2002 (28.40oC-28.86oC). However, in 2006 the temperature decreases significantly to 28.37oC below 2002 temperatures in all LGAs. This variation could be attributed to the economic crisis/power outage in Nigeria which left manufacturing companies out of production/manufacturing between 2002 and 2006. Findings from this study reveals that there is a relationship between the surface temperature and the various Land Cover types. It shows a broad classification of the Land Cover types into Water bodies, Vegetation and Built-up areas respectively. With the spatial resolution and temporal coverage of two Landsat data of the environment, the derivation of the temperature information was achieved.
Authors:EO Odoh, NI Urenyang Abstract: The reverberation times of some selected lecture theatres in Federal University of Technology, Yola which are the major contributory factors to their acoustic properties have been studied. The selected halls chosen as representatives are LT I, SMIT LT I and LT III having room volumes of 1473.4, 2156.4 and 763.0 m3 respectively. Using acoustic standards the reverberation times were computed using the Sabine formula. The result shows that the reverberation times were 4.20, 1.80 and 2.17 s respectively when they were unoccupied. To understand their acoustic behavior when occupied, the reverberation times were recomputed with assumed human audience at various capacities. When full audience was assumed, their reverberation times reduced to 1.80, 0.90 and 0.62 s for LT I, SMIT LT I and LT III respectively. The values reduced further to 0.86, 0.80 and 0.46 s respectively when the audience was increased 50% above their normal capacities. The reverberation times dropped to 0.68, 0.67 and 0.36 s respectively on doubling the audience. This results shows that in its unoccupied state, the reverberation time of 4.20 s for LT I is too high for lecture theatre which by standard should have a reverberation time of about 1.0 s. On the other hand, occupying LT III 50 % above its normal capacity means that the sound power level would rapidly decay and consequently would render audibility problematic. The reverberation times of 0.9 and 0.62 s at full occupation of SMIT LT I and LT III showed their reverberation times were still under the generally preferred value for speech rooms like lecture theatres. This is also true of all the theatres when assumed filled, one-half times above their seating capacities. Under all conditions of the investigation, it was observed that SMIT LT I seemed to show more compatibility in the reverberation time. This could be attributed to the upholstered finishes on the chairs that have higher absorption coefficient than wood in the other theatres and possible choice of room volume to absorption power ratio.
Authors:TO Oladinrin, DR Ogunsemi, IO Aje Abstract: The construction industry plays an important role in the economy, and the activities of the industry are also vital to the achievement of national socio-economic development goals of providing shelter, infrastructure and employment. It is clear that construction activities affect nearly every aspect of the economy and that the industry is vital to the continued growth of the economy. Surprisingly, the construction industry was left out from the list of major growth drivers of the economy. In order for construction to ably perform this role, there is a need to provide information on its economic value and its place in the overall economy of a country needs to be placed in perspective, if its function is to be fully understood. This study attempted to investigate the relationship between the construction sector and aggregate economy. Time series data from 1990 - 2009 on construction output and Gross Domestic Product (GDP) used for the study were extracted from the United Nation Statistic Division. This paper uses econometric techniques such as unit root test, cointegration test as well as Granger causality test to analyze the significance of construction linkage with the aggregate economy. The result indicates that construction output is Granger caused by GDP, while the construction output also granger causes the GDP. Both GDP and construction output lead each other by one year. The study concluded that the Nigerian construction sector is very important because of its capacity to lead the economy of Nigeria.
Authors:AE Oke, OT Ibironke, UA Evue Abstract: The upward trends in housing construction costs have been a major issue in the economy as a whole. The research uses typical 3 - bedroom bungalow in Lagos to analyze the trends in housing construction cost from 2000 to 2009. The basic question for this research is whether the inflation in housing construction costs between 2000 and 2009 is statistically significant. The index number and one sample t test were used to analyze the data. The findings show that costs maintained upward trends throughout the study period. The analysis shows that between 2000 and 2009, the average annual inflation in costs and inflation were significant at 11.27% and 268.88% respectively. The incessant increase in the cost of housing construction has contributed to shortage in housing supply leading to high cost of urban housing accommodation, construction estimates losing usefulness within short periods, difficulty in forecasting and planning and frequent contract price variations, which can lead to abandonment of projects. The recommendation is that government should execute policies to lower the inflation rates so that prices in the cost of housing materials would come down. Government should also provide public housing and appropriate infrastructure for the masses.
Authors:PC Nwilo, DN Olayinka, CJ Okolie, EA Adzandeh Abstract: Determination of height information using the classical field surveying and geodetic methods is rather expensive, rigorous and time consuming. It is also limited in the capacity of the earth surface data gathered. These conventional topographic mapping technologies have produced maps with a variety of scales and of uneven quality - some with astounding accuracy, some far less adequate. A good alternative is the Shuttle Radar Topography Mission (SRTM) derived Digital Elevation Model (DEM) which provides an excellent base data for extracting heights for topographic mapping. This will ameliorate the present situation. The SRTM space mission produced the most complete, highest resolution digital elevation model of the Earth. This study is aimed at developing a model for the transformation of the SRTM heights from WGS84 datum to the Nigerian height system (Minna datum) using SRTM derived DEM, topographic map and Global Positioning System (GPS) data of some parts of Lagos state, Nigeria. The chosen site corresponds to the area covered by one map sheet at the scale of 1:25,000 (13.8km x 13.8km) which is 190.44sq.km. Software such as Globalmapper, Surfer 8.0 and ArcGIS 9.3 were used for specialized data processing and analysis. However, the datasets obtainedwere first projected to a common system and subsequently harmonized. This was carried out with an overlay of GPS points on the grid based SRTM and topographic DEM surfaces of the environment. Results showed deviation in heights with coinciding planimetry data. The average absolute error of the SRTM DEM for our test site was gotten as +/-0.22087m. Finally, by modelling this vertical shift, a transformation model that is accurate with a standard error of 0.238m was developed.
Authors:CP Ogbu, CF Asuquo, AJ Oyoh Abstract: Debates over the preparation, use and relevance of the Bill Of Quantities (BOQ) in the construction industry have been long standing without commensurate research effort to address the problem. The objectives of this research are to determine the extent of use of the BOQ in the Nigerian construction industry, evaluate the criteria for the use/benefits of the use of the BOQ and to evaluate the factors mitigating the use of the BOQ. Data were collected through the administration of questionnaire on 53 randomly selected construction consultants. Majority of the respondents (47.2%) were quantity surveyors, 20.8% were builders, 17% were architects, 9.4% were civil engineers and 5.7% were mechanical and electrical engineers. The data collected were analysed with the Statistical Package for Social Sciences (SPSS) using descriptive statistics and analysis of variance. Key findings are that use of the BOQ constitutes 46.35% of construction professionals’ overall workload, and the most important benefit of the use of BOQs in Nigeria is that they provide common bases for competitive bidding. The five most important factors mitigating the use of the BOQ at the pre-contract stage are: limitation in scope and spread of dedicated computer software for BOQ preparation, Absence/lack of implementation of legislations compelling the use of the BOQ, BOQs are not supported by emerging procurement systems, BOQs are expensive to prepare and lack of complete information on which to base the BOQ. This research provides useful information on the strength of the factors affecting the use of the BOQ at the pre-contract stage.
Authors:CI Ikhile Abstract: An examination of peoples’ awareness and response to environmental pollution in Benin Municipality, Nigeria was investigated. The questionnaire instrument was utilized in the survey. Two hundred and fifty questionnaires were administered at five randomly selected areas in five selected wards in May 2010. Analysis was carried out using simple percentages and frequency tables. The three most serious types of environmental pollution were listed as noise (35%), air (26%), water (20%) and land (18%). Street flood scored 59%, flood pondages recorded 37%, while river flood scored 4%. The causes of flooding includes: insufficient drainage facilities to cope with excess rainfall (30%), excessive rainfall (28%), building along drainage pathways (30%), while concreting of urban surfaces was 12%. The concepts of environmental pollution, protection and preservation and the involvement of the respondents have not been fully understood by majority of the respondents. Issue No:Vol. 7, No. 1
Authors:IO Famakin, SA Makanjuola, O Adeniyi, TO Oladinrin Abstract: The effectiveness of the construction industry can only be enhanced by repositioning the construction health and safety regulations to safeguard the health of the workers and the entire community. This paper seeks to assess the views of consultants and contractors about the impact of construction health and safety regulations in Nigeria. Data was collected using the questionnaire survey distributed among construction professionals and statistical tools employed include tables, percentages and mean score ranking. The study revealed that construction health and safety is still perceived to be more important than the traditional project parameters in the form of cost, time and quality. Designers perceive that an enhanced environment is the resultant impact of construction health and safety regulations while quantity surveyors see improved quality as having the resultant impact while contractors perceive improved maintenance as having the resultant impact on health and safety regulation. The study recommends that better attention is given to health and safety should as a project parameter and that related practice notes and guidelines should be evolved for all project stakeholders.
Authors:JO Owoeye, O Sogbon Abstract: Most indigenous cities of emerging nations in the third world are characterized by large-scale housing and environmental deficiencies. This paper attempts to investigate the limiting role of socio-cultural attributes of slum residents on renewal policies which are implemented to minimize or eradicate such deficiencies. The study was carried out in Akure, in South-Western Nigeria. Using questionnaires, direct observation, housing demographic and facility survey for data collection, it was discovered that residence satisfaction is not to be measured only by the facilities therein or by the quality of the dwelling units. Other imperceptible cultural and social factors play prominent roles, which need be considered while framing policies for city development. However, full participation of slum residents is noted very indispensable for the success of any large scale renewal programme while effective public enlightenment, improved socio-economic base and sanitary education strategies will help in re-orientating the people and equipping them towards healthy and aesthetically decent environment.
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