Water Resources Uncertainty in Yewa River Basin, Ogun state, South-West Nigeria

The paper examined water resources insecurity arising from climatic change and variability, coupled with increased population and economic development in in Yewa basin, with a view to understanding the relationship between climatic variables and hydrological parameters operating within the basin. Thus, the study entails assessment of the effects of climate change and variability on water resources and its implication on both the physical environment and the hydrological regime, using the water evaluation and planning (WEAP) system model. Data employed included water supply and demand for Domestic, Commercial, Industrial and Agriculture, as well as climatic data (rainfall and Temperature) and runoff. As revealed by the Scenario fabrication, 45.24% of the annual water requirement within Yewa Basin is not met, with water potentials of Annual mean discharge of 3682.46 m3/s (±830.1) and Annual mean rainfall of 1106.26m (±475.25), and with coefficients of variation of 40.88 and 73.73, respectively. This deficit calls for an appropriate water resources management mechanism to be put into use in Yewa Basin.