Onitsha is one of the largest commercial cities in Africa with its population growth rate increasing arithmetically for the past two decades. This situation has direct and indirect effects on the natural resources including vegetation and water. The study aimed at assessing land use-land cover (LULC) change and its effects on the vegetation and landscape from 1987 to 2015 using geoinformatics. Supervised and unsupervised classifications including maximum likelihood algorithm were performed using ENVI 4.7 and ArcGIS 10.1 versions. The LULC was classified into 7 classes: built-up areas (settlement), waterbody, thick vegetation, light vegetation, riparian vegetation, sand deposit (bare soil) and floodplain. The result revealed that all the three vegetation types decreased in areas throughout the study period while, settlement, sand deposit and floodplain areas have remarkable increase of about 100% in 2015 when compared with the total in 1987. Number of dominant plant species decreased continuously during the study. The overall classification accuracies in 1987, 2002 and 2015 was 90.7%, 92.9% and 95.5% respectively. The overall kappa coefficient of the image classification for 1987, 2002 and 2015 was 0.98, 0.93 and 0.96 respectively. In general, the average classification was above 90%, a proof that the classification was reliable and acceptable.

The study was carried out to investigate the different groundwater resources and to generate the temporal differences over the different seasons in Ilesa West Local Government, Osun State, Nigeria. The LGA has not been provided with municipal pipe-borne water supply for over 30 years, hence they are exclusively using groundwater in form of boreholes, dugwells and springs. The physico- chemical and heavy metal parameters were determined over a period of one year covering the rainy and dry seasons. A total of 69 drinking water points which comprises of 63 dugwells, 5 boreholes and 1 spring were used for the study and they were selected to represent the built-up part of the entire study area adequately. Parameters analysed were pH, electrical conductivity (EC), temperature, total dissolved solids (TDS), chloride, sulphate, nitrate, sodium, potassium (K), calcium, magnesium, hardness, alkalinity, bicarbonate using standard methods. Analysis of heavy metals (Fe, Cr) was carried out with atomic absorption spectrophotometer (AAS) and microbiological analysis was conducted using most probable number (MPN) of counting coliforms. The data generated were subjected to descriptive statistics and line graph. The analysis of the different groundwater resources revealed a good water quality but the values of pH, TDS, EC, K, were higher than the permissible range. The concentration of Fe and Cr is very high and could constitute some health hazards in some sources. The temporal variation of the water quality parameters did not follow any definite trend but the pH, NO3, TDS, HCO3, SO4, Fe, Cr were highest in the dry months of April and December, while Ca, Mg, K, Na, hardness, and alkalinity were highest in the rainy months of June and August. The percentage of microbial distribution was highest in the months of June in the boreholes and the spring but the distribution in the dugwells was entirely different. The water from the boreholes and dugwells were generally soft and should be checked for plumbo-solvency. It is recommended that a routine monitoring of all the sources should be carried out and a treatment that will reduce the heavy metals concentrations be enforced. Keywords: Groundwater resources, physico-chemical parameters, temporal variations, dugwells, boreholes and spring.

Activities in building construction industry contribute to air pollution. In this study, gas data from four locations at each three building construction sites in Doha, Qatar were collected and analyzed. Questionnaires were also administered to companies that are involved in building construction projects. The results showed traces of SO2, CO2, CO and NO2 but in amounts below the detrimental limit stipulated by the Ministry of Environment, Qatar. Questionnaire responses revealed that the extraction of raw materials and the energy consumed during construction occur quite often, but strongly implicated dust generated from construction sites and waste disposal, as major factors causing air pollution in the area. It is therefore, recommended that regular monitoring of air should be carried out within building construction sites to aid detection of air contamination. This will serve as a control measure to stimulate catalytic conversion of exhaust, reuse and recycling of waste materials. Keywords: Air pollution, Building construction activities, Dust, Emissions and Environment.

The study assessed the quality management practices as it affects the building projects in Osogbo, Osun State, Nigeria with a view to determining the causes of building failure. The work involved the distribution of questionnaires and a follow-up study on respondents. The questionnaires were designed to extract information from the stakeholders: professionals from Ministry of Works and Housing, contractors, and direct users of the projects on the general causes of building collapse in relation to quality management. To have a good representation of the study area, one hundred and twenty (120) copies of questionnaire were administered using Taro Yamani method of sample size determination. A total of 92 questionnaires were retrieved and the results were subjected to descriptive and inferential statistical analysis. The study revealed that handling of the construction process by unqualified and quacks, possession of approved drawing without compliance and usage of substandard building materials were the major causes of building collapse. It was recommended that there should be constant evaluation of contractors and other players to determine the level of compliance to quality standards as prescribed by the regulatory bodies to curb the incidences of building collapse.

This paper reports the study of groundwater quality assessment in Boluwaduro community, Ofatedo in Osun State. In addition, it utilized the Artificial Neural Network (ANN) tool in MATLAB Software to simulate the water quality parameters/contaminants. Water samples were taken from 18 randomly selected dugwells and subjected to physico-chemicals and microbiological analysis. The mean concentrations of nitrate, nitrite, lead and iron are 20.12 mg/L, 0.78 mg/L, 0.159 mg/L and 0.35 mg/L respectively. Total plate counts range between 27 – 96 cfu/mL with growth in all the water samples. The ANN structure was trained in several rounds till satisfactory output was obtained with correlation value of R2 = 0.97. Simulation of the pH using ANN provides a good match at 10% increment of chloride, nitrate and iron and the pH value of the water sources increased with the corresponding increase in the concentrations of the parameters. The generated model for TDS gave a good prediction with total hardness and magnesium respectively. The concentrations of some metals in the wells are not safe for drinking; it could pose danger to users of the water sources. It is therefore recommended that the wells in the community should be subjected to routine monitoring and treatment of the contaminants should be enforced.

This study investigates the effects of waste glass as a replacement for fine and coarse aggregates on the strength properties of concrete. Fine waste glass (FWG) and coarse waste glass (CWG) were utilised to replace natural fine and coarse aggregates at replacement rates of 0%, 10%, 15%, and 20%, with a constant water-to-binder (w/b) ratio of 0.5 and a mix ratio of 1:1½:3 for M25 grade. The workability of fresh concrete mix was determined with the slump test. To assess the hardened characteristics of concrete, compressive and tensile strength tests were performed at 7, 14, and 28 days’ curing ages. The results show that the workability of concrete decreases as the FWG and CWG contents in the concrete mix increase. The 28-day compressive and tensile strengths of concrete increased by 28% and 16% respectively, with the replacement of up to 15% FWG and CWG, respectively compared to the control. However, the compressive and tensile strengths of concrete reduces with further replacement of fine and coarse aggregate with waste glass. The strength properties of concrete are improved at the optimum permissible level of 15% FWG and CWG, respectively, as a substitute for conventional fine and coarse aggregates. It was concluded that using waste glass as a constituent material in concrete production is a viable option for disposing of waste glass and lowering concrete production costs.

The use of industrial by-products in concrete production is part of concerted efforts on the reduction of environmental hazards attributed to the mining of conventional aggregates. Consideration of iron filings (IF), a by-product from steel production process, is an environmentally friendly way of its disposal which is expected to yield economic concrete production. Six self-compacting concrete (SCC) mixes were made by partially substituting river sand with IF at 5%, 10%, 15%, and 20% and the mix without IF (0% IF) served as the control. The water-binder (w/b) ratio of 0.45 was adopted for all mixes. The fresh state properties of SCC evaluated include: filling ability determined using slump flow and T500 mm slump flow tests, passing ability determined using L-box test and segregation resistance determined using V-funnel tests. The strength properties of SCC considered were compressive and tensile strengths. All the SCC mixes met the fresh properties requirements for filling capacity, passing ability, and segregation resistance. The 28-day compressive and tensile strengths of SCC increased by 3.46% and 8.08%, respectively, with IF replacement up to 15% compared to the control SCC. However, there was reduction in compressive and tensile strengths of SCC with IF replacement beyond 15%. The strength properties of SCC is considerably enhanced with the addition of up to 15% IF. Hence, the optimum content of 15% IF is considered suitable as a replacement for river sand in SCC. Keywords: Self-compacting concrete; iron filings; fine aggregates; filling ability; passing ability

This study assessed the water metering and billing methods in some parts of Osogbo metropolis of Osun State, Nigeria by evaluating the adequacy, effectiveness and cost implications of the systems. Data was obtained through a questionnaire survey, field observations and oral interviews. A total number of 200 questionnaires were randomly distributed to the households around the metered neighbourhood, 173 responses were retrieved for analysis. It was discovered that the waterworks only have a metering system for 3222 (0.85%) households. It charges a fixed price of ₦2000/month for those without water meters and ₦2700/month for metered households. The percentages of domestic, industrial, religious, governmental and institutional water users were 41.6%, 30.6%, 8.7%, 8.1% and 11.0% respectively and a majority of the water users agreed to be consuming between 75 – 100 litres of water per day. Considering the number of days that households get water, the study found that in a week, 16.8%, 46.8% and 36.4% of the respondents get water for, 1-2, 2-4, and 4-7days respectively. The study revealed that 9.8%, 23.1%, 48.6% and 18.5% of the respondents were 5-20%, 21-40%, 41- 60% and 61-80% satisfied with their billing methods respectively. If water is available all the days of the week, the study found the billing system to be fair. Residents are then advised to subscribe to the metering and billing systems for fair bargaining.