Modelling of the Sediment Yield and Sediment Concentration along Idemili River Water Shed. Anambra State

Abstract

Water is a necessary element that is useful for survival of human being, animal and plants. Water exists as streams, rivers, lakes and oceans. Naturally, it is observed that overtime the volume of water that exists in the natural reservoirs of streams and rivers reduces due to inflow of sands, stone, debris and other sediments in the water. This sediment yield and concentration if not properly managed reduces water volume thereby causing scarcity. Modeling the sediment yield, sediment concentration in River Idemili in Anambra State is necessary to determine the rate and quantity of sediment inflow into the river so as to proffer solution on how to reduce the sediment inflow and solve water scarcity. The tools used for the modeling are GIS, Land use, soil maps and climate data such as temperature, humidity, rainfall data etc. The data were imputed into the MAPWINDOW GIS to analyze and predict sediment yield and concentration in River Idemili from the period of 1999 to 2021. Results from the analysis reveals that there are nine sub-basin in the catchment area. River Idemili falls within sub-basin 5 and 6. Result shows that maximum yield in the sub-basin are 23.3686t/ha and the maximum sediment concentration in the Idemili River stand at 38.709mg/c. Controling the sediment yield and concentration, the indiscriminant falling of trees, aggressive removing of vegetative cover should be reduced so that soil surface are not exposed to erosion that will carry the loose soil, silt and plant remains into the River Idemili.