Sediment Yield Modeling Using SWAT Model: Case of Changjiang River Basin

Abstract

Soil erosion is posing a severe challenge to the productivity of land throughout the word, this alarming situation requires urgent interventions in order to preserve water and soil resources. This study presents an application of the model Soil and Water Assessment Tool(SWAT) to simulate daily and monthly water flow and sediment load from 1980 to 2012 in the Changjiang River basin, which is a sub-basin of the Poyang Lake basin, China. The sensitivity analysis is carried out by using the LH-OAT method. The model was calibrated and validated based on a comparison of simulated and measured runoff and sediment data of the Tankou and Dufengken hydrological station in Changjiang River. Indeed, for the monthly time step application, the relative error of the model to the runoff simulation was less than 10.21% in the calibration period and the validation period. The correlation coefficient(R2) and Nash-Suttcliffe(Ens) were higher than or equal to 0.91, and The relative error of the model to the sediment simulation was less than 26.0% in the calibration period and the validation period, R2 and Ens were higher than 0.76. The research indicates that SWAT model can be used to simulate the runoff and sediment, water loss and soil erosion are mainly caused by rainfall in flood season, and the sediment is up to 99.26% of the total year, and it has a good correlation among rainfall, runoff and sediment in flood period.