Anthropogenic influences on the variation of runoff and sediment load of the Mahanadi River basin

The emphasis of the present study is on trends and abrupt change points for the runoff and sediment load in a major river basin and anthropogenic factors that influence these trends. The methods adopted are the Mann-Kendall, Sen's slope, and Pettitt tests for trend and change detection; the difference in digital elevation model for coastal morphological changes; and the double mass curve technique for relative proportions of anthropogenic factors. Significant decreasing trends in yearly runoff and sediment load are observed for 13% and 69% of the hydrological stations, respectively. The analysis found a 79% reduction in sediment discharge into the sea. A figure showing zones of vertical erosion and accretion is also displayed. Geomorphic changes indicate that the landforms susceptible to areal erosion are vulnerable to vertical land loss. Upstream damming, increasing demand, and water allocations are the crucial anthropogenic factors responsible for reducing the sediment load of the basin.