Effects of Land Use on the Chemical Characterization of Imo River Basin and Its Catchments (Nigeria): A GIS Approach

Water sources have been severely contaminated by heavy metals (HM) in Imo river basin due to different land uses including industrialization and intensive agriculture. Six land use types were identified using GIS and water samples were collected from both surface and underground water sources to test the HM concentrations in different land uses. Geostatistical tools such as interpolation (Kriging) and regressions were used to determine the extent of chemical concentrations, and their relationships with the land use types. Higher concentrations of the heavy metals (NO3, Cr, and Pb) were observed in the center (middle stream watershed) around the urban built and grassland areas. Downstream watershed (wetlands areas) had low concentrations of the HM except Fe. The water quality in the built-up industrial areas were found to be of poor quality relative to other parts in the study area. The findings of this work will support the Federal Ministries of Water resources, Agriculture, Environment in sustainable decision making towards reducing pollutants and restoring the river basin and its catchments.