APPLICATION OF SWAT MODEL IN THE UPSTREAM WATERSHED OF THE LUOHE RIVER

In the Huanghe (Yellow) River basin, soil erosion is a serious problem, while runoff and sediment yield simulation has not been extensively studied on the basis of GIS (Geographic Information System) and distributed hydrological model. GIS-based SWAT (Soil and Water Assessment Tool) model was used to simulate runoff and sediment in the Huanghe River basin. The objective of this paper is to examine the applicability of SWAT model in a large river basin with high sediment runoff modulus, which could reach 770t/(km(2).a). A two-stage "Brute Force" optimization procedure was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997, and with input parameters set during the calibration process without any change the model was validated with 1998-1999's observed data. Coefficient of examination (R(2)) and Nash-Suttcliffe simulation efficiency (E(ns)) were used to evaluate model prediction. The evaluation coefficients for simulated flow and sediment, and observed flow and sediment were all above 0.7, which shows that SWAT model could be a useful tool for water resources and soil conservation planning in the Huanghe River basin.