基于ArcSwat模型的李子溪流域水沙运移模拟

Water and Sediment Transport Simulation in Lizixi River Basin Based on ArcSwat Model

为了模拟李子溪流域水沙运移,掌握流域内土地利用变化和气候变化对流域产流和产沙的影响,基于流域基础数据构建ArcSwat模型,模型结果表明该模型对年径流、年泥沙量、月径流模拟精度较高,而月泥沙量模拟精度较低。通过设置不同情境得到以下结论:土地利用改变对产沙的影响较产流大,在涵养水源和拦截泥沙方面,林地>草地>耕地,在大于25°的坡耕地上实施还林还草措施拦沙减流的效果更明显;气候变化对产沙的影响比产流大,产流、产沙与降雨呈正相关关系,与温度呈负相关关系,降雨量的变化对产流和产沙的影响比温度大。

In order to simulate the water and sediment transport in Lizixi River Basin and grasp the impacts of land use and climate changes on runoff and sediment yields,this paper builds the ArcSwat model based on basic data of basin,and indicates that the simulation accuracy of the model for annual runoff,annual sediment volume and monthly runoff is high,while that for monthly sediment volume is low.Through setting up different scenarios,the following conclusions can be drawn:Land use change has greater impact on sediment yield than runoff yield,in terms of water conservation and sediment interception,forest land>grassland>arable land;and in arable land with slop of more than 25 degrees,the effect of returning arable land to forest land and grassland to reduce sediment and runoff is more obvious;Climate change has a greater impact on sediment yield than runoff yield,the runoff and sediment yields are positively correlated with rainfall,and negatively correlated with temperature;and rainfall has a greater impact on runoff and sediment yields than temperature.