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分布式侵蚀产沙模型是土壤侵蚀模型的重要发展方向,本研究将蛇家沟流域下垫面划分为5×5m的栅格,每个栅格内赋予相应的高程、坡度、地貌、土地利用等属性信息。根据流域DEM,确定流域的汇流方向、流路与汇流累积面积。在蛇家沟流域内采用“穷举算法”对SCS-CN模型的参数值进行校正。基于DEM、地貌、土地利用以及降雨等资料,利用黄土丘陵沟壑区良好的水沙关系,运用VB.NET+ARC ENGINE9.2+SQLSERVER2000构建分布式侵蚀产沙模型。模型结构简单,输入参数比较少,利用求产流来求产沙,考虑了土地利用、汇流等因素具有一定的物理意义,并能达到一定的预报精度。其中产沙模型是建立在黄土丘陵沟壑区普遍的水沙关系基础上,通过校正水沙关系式系数及产流模型中的CN、λ值可在其它相似的小流域内使用。该研究可为黄土丘陵沟壑区水土保持治理效果评价提供依据。
Distributed erosion and sediment yield model is an important development direction of soil erosion model. In this study, the underlying surface of the Shejiagou Watershed was divided into 5 × 5m grids, and each grid was given corresponding elevation, slope, landform and land use Such as property information. According to the basin DEM, determine the confluence direction of the catchment, the cumulative area of the flow path and the confluence. In the Shejiagou Watershed, the “Exhaustive Algorithm” was used to correct the parameter values of SCS-CN model. Based on the data of DEM, landform, land use and rainfall, and using the good relationship between water and sediment in the hilly and gully regions of the Loess Plateau, a distributed erosion and sediment yield model was constructed by using VB.NET + ARC ENGINE9.2 + SQLSERVER2000. The model has the advantages of simple structure, relatively few input parameters, demand of runoff to seek for sand production, taking into account factors such as land use and confluence, which have certain physical significance and can reach certain forecast accuracy. The sand production model is based on the common relationship between water and sediment in the gully area of the Loess Plateau. It can be used in other similar small watershed by correcting the coefficient of water and sediment and the CN and λ values in the runoff model. This study can provide basis for evaluating the effect of soil and water conservation in loess hilly and gully regions.