Surface runoff modeling of Lake Fuxian catchment

Abstract

采用适用于无资料流域、参数较少的SCS模型计算抚仙湖集水域地表径流量.模型考虑了集水域下垫面条件的空间差异,利用Maplnfo/Arc view软件按照土地利用方式与土壤类型的不同,把集水域划分为若干个水文响应单元,分别计算产流量,较准确地模拟了入湖径流量.通过对梁王河流域和大鲫鱼沟流域实测降雨径流资料的分析与反演,提出了适合该区域的产流计算CN值.在对CN值作坡度修正后再应用到其它无观测数据区域.通过模型计算得到的抚仙湖集水域2005年3月1日-2006年2月28日地表径流量为1.74×10⁸ m³,陆面径流系数为0.395.模型为指导抚仙湖集水域径流观测及入湖污染物负荷的计算提供依据.;SCS model is adopted in this paper to simulate surface runoff' for Lake Fuxian catchment. The modelconsiders the spatial diversities of the Iand surface via dividing the catchment into a number of hydrological responseunits(HRU) based on diH'erent landuses and soil types. The surface runoff for each HRU is calculated and the totat surface runoff into the lake is modeled. CN values of the SCS model are calibrated场matching the modeled resulfa with the observed ones for the gauged river catchments of Liangwanghe and Dajiyugou. The model is then opplied to other ungauged areas of Lake Fuxian catchment after making slope corrections of the CN values. The modelindicates that the total surface runoff is 174 million ms for a one-year period of March 2005 to February 2006,withan average runoff cae}cient of 0. 395. The model is believed to be helpful in guiding further field observations. Themodeled results are also useful in constructing more detailed hydrological models as the next step, and in calculating mass of pollutants loaded to the lake.