APEX模型在淮河中上游坡面尺度的适宜性研究

为评价农业政策与环境拓展APEX模型在淮河中上游坡面尺度的适宜性,将其应用于淮河中上游的3个径流小区,在采用傅里叶幅度灵敏度检验扩展法进行灵敏度分析的基础上,利用蒙特卡罗模拟结合多目标函数技术自动校正模型,并使用1982-1986年日径流和产沙数据实测值与模拟值评价模型适宜性.结果表明:湿度条件2下的径流曲线数初始值(CN2)、损耗系数(CNIC)、水土保持措施因子(PEC)以及最大径流率-降雨能量调整因子(APM)对产沙模拟影响较大,CN2和CNIC对地表径流模拟影响较大；在模型校正阶段,径流和产沙日平均模拟值的百分误差绝对值(APE)小于20％,纳希-苏特克利夫有效系数(EF)和R2分别大于0.45和0.55;在模型验证阶段,径流和产沙日平均模拟值的APE小于25％,EF和R2分别大于0.4和0.5.这说明APEX模型适用于淮河中上游坡面尺度,可用于评价该地区不同土地管理措施下的水土流失.

Applicability of APEX model for slope scale in the Middle and Upland Huaihe River

This study was conducted to evaluate the applicability of Agricultural Policy Environmental eXtender(APEX) model using daily runoff and sediment yield(1982—1986) collected from three plots located in the Middle and Upland Huaihe River.Sensitivity analysis was conducted for the surface runoff and soil erosion components using Extended Fourier amplitude sensitivity test.Then the automatic calibration procedure was used for this study,which utilized Monte Carlo simulation and multi-objective function techniques.Moisture condition 2 curve number(CN2),curve number index coefficient(CNIC),conservation practice factor(PEC),and peak rate-rainfall energy adjustment factor(APM) were influential for sediment yield,and that CN2 and CNIC were influential for surface runoff.The absolute value of the percent errors of mean was within 20%,with Nash-Sutcliffe efficiency and R2 values above 0.45 and 0.55 respectively for both daily runoff and sediment yield for the three plots during the calibration period.For the validation period,the APE was within 25%,with the EF and R2 values above 0.4 and 0.5 respectively.The results show that APEX model is applicable to slope scale and is a useful tool for assessing soil and water loss for different management practices in the Middle and Upland Huaihe River.