Assessment of Water Quality Using Remote Sensing in Kainji Lake, Niger State

Kainji Lake, one of Nigeria's largest man-made water bodies located in Niger State, supports artisanal fishing, irrigation, and hydropower generation. Increasing sedimentation and agricultural runoff have raised concerns about water quality deterioration. This study applies remote sensing techniques to assess spatial variations in water quality parameters including turbidity, chlorophyll-a concentration, and total suspended solids across Kainji Lake. Sentinel-2 multispectral bands are used to derive spectral indices sensitive to water constituents, while in-situ measurements collected at 20 sampling stations validate the spectral retrievals. Regression analysis establishes relationships between reflectance values and measured water quality parameters, achieving correlation coefficients ranging from 0.74 to 0.89. Results indicate elevated turbidity concentrations in the lake's northern sections near river inflow points from the Oli and Majiya tributaries. Seasonal variations linked to the rainy season flush of sediments from upstream agricultural areas are documented. The study recommends the establishment of a remote sensing-based water quality monitoring system for Kainji Lake as a cost-effective complement to conventional field sampling. Findings are directed at the Kainji Lake Research Institute and the Niger State Environmental Protection Agency. Keywords: water quality, remote sensing, Kainji Lake, turbidity, chlorophyll-a