OYAKHILOME EFUAYE EUNICE

This study evaluates the spatiotemporal changes of land use/land cover (LULC) and vegetation cover in a mapped area of the Ikpoba River catchment in Benin City, Nigeria, from 1965 to 2025 and ascertains the impact of these changes on the rivers’ physicochemical water quality. Geospatial tools, such as the Normalized Difference Vegetation Index (NDVI), were used to map land use/land cover (LULC) and vegetation health changes over the sixty-year period. Water samples were collected monthly from three sampling points for a three-month period (May to July 2025) and underwent physicochemical analysis. Analysis revealed a substantial decline in vegetation cover driven by urbanization and infrastructural development. The land cover was overwhelmingly dominated by built-up areas in the latter years (2015 and 2025), a trend that began with the appearance of built-up areas in 1995. Water analysis showed variable pH values, along with high electrical conductivity (EC), total suspended solids (TSS), and turbidity levels. Specifically, turbidity readings (up to 40.00 NTU) significantly exceeded the WHO drinking water limit of 5.00 NTU, indicating severe sediment loading, and pH values exhibited a trend toward the acidic lower limit. These results make it clear that immediate action is needed to better handle waste, stop erosion, plan land use wisely and constantly check the water quality. Implementing these strategies will ensure the long-term protection of the Ikpoba River, maintain ecological stability and secure community members' access to water resources.