Temi Emmanuel Ologunorisa

The study analyzed urban growth (UG) and land surface temperature (LST) of Asaba and Abuja in Nigeria from 1986 to 2022. Landsat 5 TM imagery of 1986, Landsat 7 ETM of 2000, and Landsat OLI/TIRS of 2022, of 30m resolutions, were obtained for the determination of both LST and UG analyses. The UG analysis was subjected to the supervised classification of the maximum likelihood module to generate the different land use/ land cover of the study area. Descriptive statistics involving the frequency and percentage were used for the data analysis. Findings from the study revealed that the mean LST, which was 33.38 °C in 1986, decreased to 28.25 in 2002 and subsequently 28.98oC in 2022, while the built-up Area representing urban development increased from 14% in 1986 to 65% in 2022. The UG was significantly increasing at the rate of 242% while LST increased at 7 °C within the period under consideration. The study concludes that the increase in the built-up area is responsible for the increase in the land surface temperature in Asaba and Abuja Metropolis. The authors recommend that LST parameters be taken into consideration for sustainable urban planning to be achieved in the city. Policymakers at all levels need to scale up measures to mitigate the adverse impact of urban heat islands by suggesting a clustered greening of the entire urban landscape. The study has also provided pathways in addressing the complexity of land surface temperature and the future urban development of the city of Asaba and Abuja.

The influence of changes in season on heavy metal concentrations in rural groundwater of Benue State is investigated in this study. Water samples were collected from 26 rural community boreholes and analyzed for heavy metal concentrations as they affect the quality of drinking water based on the WHO standard and their variability for both wet and dry seasons. The analyses were carried out as prescribed in the standard methods for examination of water. The results of analyses show the mean values and CV% as follows: pH 7.55; 6.21% for wet season and 8.89; 4.24% for dry season. 414 µS/cm; 137.58% for wet season and 272.13 µS/cm; 94.92% for dry season; Fe 0.82 mg/L; 81.71% for wet season and 0.03 mg/L; 324% for dry season; Mn 0.73 mg/L; 52.05% for wet season and 0.14 mg/L; 92% for dry season; Zn 0.10 mg/L; 140% for wet season and 0.13 mg/L; 130.76% for dry season; Pb 0.74 mg/L; 75.68% for wet season and 0.04 mg/L; 170% for dry season; Cu 0.88 mg/L; 64.77% for wet season and 0.00 mg/L; 60% for dry season. Apart from pH and Zn whose values were higher in the dry season, other metals investigated had higher concentrations in the wet season. This implies that as climate becomes either wetter or drier due to phenomenal changes concentrations of heavy metals are likely to respond appropriately.</p