AnnAGNPS模型在黄土丘陵沟壑区小流域的适用性评价

在水土流失较严重、生态环境较脆弱的黄土丘陵沟壑区定量化研究土壤侵蚀对于合理利用土地及保护环境显得尤为重要。本文运用基于过程的Ann AGNPS模型对典型黄土丘陵沟壑区-岔口小流域的水土流失进行模拟,以5场次暴雨径流量及泥沙量评价模型适用性。模拟结果表明:模型能较好的模拟地表径流,模拟相对误差为-21.46%~2.26%,确定性系数R2为0.99,Nash-Sutcliffe系数为0.99。模型对泥沙模拟精度较低。对岔口小流域土壤侵蚀定量分析表明,单位面积泥沙流失量最严重的区域集中在坡耕地上,尤以核桃树与玉米间种的坡耕地流失最大。

Suitability evaluation of AnnAGNPS model in Chakou watershed of typical loess hilly region

The quantitative evaluation of soil erosion is of great importance for the rational land utilization and environment protection in the typical loess hilly region with a serious soil erosion and vulnerable ecological environment.This paper applied AnnAGNPS model which based on process to simulate the soil erosion in Chakou watershed. The applicability of model was validated by using the measured data of runoff and sediment load of five storms.The results indicated that AnnAGNPS model can better simulate surface runoff, the relative error of runoff is from -21.46% to 2.26% (R²=0.99, E=0.99). While the simulation accuracy of the model to sediment is low. The results indicated that the most serious soil erosion of sediment volume per unit area occurred in slope cropland, especially the slope cropland with the walnut trees and corn.