基于地理信息的SCS模型及其在黄土高原典型流域降雨-径流关系中的应用

基于土地利用、土壤类型等信息数据和流域水文、气象资料,应用美国农业部水土保持局研制的小流域设计洪水模型-SCS模型对王东沟流域径流过程进行了模拟.按照集水区自然分水线划分流域子单元,并提出了适合该流域产流计算的CN值表.结果表明,模型所模拟的径流过程与实测径流过程具有较好的一致性,模拟精度在75%以上,说明模型在参数的确定上是较为合理的,可以应用于黄土高原典型流域.为建立分布式水文模型对流域进行生态水文综合评价提供了科学方法.

A SCS model based on geography information and its application on rainfall-runoff of typical small watershed on loess plateau

Based on the information data of land use,soil classification,hydrology and meteorology,a SCS model,developed by Soil Conservation Service(SCS),U.S.A.,is applied to simulate the rainfall-runoff relationship in Wangdonggou small watershed.The main conclusions are as follows:(1)Wangdonggou watershed is compartmentalized by some sub-units according to natural draining division,and the table of fitting CN values for Wangdonggou watershed is presented.(2) The hydrograph of calculated runoff process by the SCS model and the hydrograph of observed runoff process coincide very well in height as well as in shape,and the model is of high prcision above 75%.It has been shown that the SCS model can successfully be used to simulate the runoff generation and the runoff process of typical watershed on loess plateau,and the SCS hydrological model is a good means to study the rainfall-runoff relationship based on the geographical or remote sensing information.