基于SWAT模型的中尺度流域产流产沙模拟研究

Runoff and Sediment Yield Modeling in Meso-scale Watershed Based on SWAT Model

以黄河下游小花间(小浪底-花园口)区域洛河卢氏水文站以上流域为研究区,在GIS技术支持下,应用分布式模型SWAT(SoilandWaterAssessmentTool)进行了流域产流产沙模拟。采用卢氏水文站1992～1997连续6年的实测月均径流和泥沙数据对模型进行了校准:在模型校准过程采用自动数字滤波技术将径流总量划分为直接径流和基流,并分别对直接径流和基流进行了校准,以达到径流总量的拟合,在此基础上对流域泥沙负荷进行了校准;采用1998～1999连续2年的实测月均径流和泥沙数据对模型的适用性进行了验证。采用相对误差(RE)、决定系数(R2)以及Nash-Suttcliffe效率系数(Ens)作为模型适用性的评价系数,结果表明SWAT模型在研究区对流域长期连续径流和泥沙负荷模拟具有较好的适用性,具有一定的推广意义。

The upper watershed of Luo River which is located in the Xiaohua District (XiaolangdiHuayuankou) was selected as the study area to validate distributed SWAT (Soil and Water Assessment Tool) model with the support of GIS technology. Monthly runoff and sediment yield data from 1992 to 1997 were used to calibrate SWAT. In the process of calibration automated digital filter technique was used to partition direct runoff and base flow. The direct runoff was firstly calibrated, then the base flow, and the total runoff were matched. At last the sediment yield was calibrated to match well. After calibration, monthly runoff volume and sediment yield data from 1998 to 1999 were used to validate SWAT model. Relative Error (RE), Determination Coefficient (R2) and NashSuttcliffe Efficiency (Ens) were used to evaluate the applicability of SWAT model, the results show that SWAT model could be successfully used to model longterm continuous runoff and sediment yield in the mesoscale watershed in the Yellow River Basin.