基于物理过程的分布式流域水沙预报模型

将分布式水文模型与土壤侵蚀产沙模型相互嵌套，构建了一个分布式流域水沙预报模型。模型基于DEM，将流域离散为“坡面+ 沟道”系统，采用“+ 1 ”分级方法将沟道组织为河网，实现了流域水沙预报的并行计算。坡面单元划分为植被层、地表层、非饱和带和地下水层，模拟了降雨、截留、蒸散发、入渗、地表径流、壤中流和地下水、各种形式的侵蚀产沙及泥沙输移；沟道进行汇流演算以及泥沙输移。模型在李子溪流域对长系列降雨的模拟结果表明，模型的水文模块模拟精度良好，侵蚀产沙模块模拟效果基本令人满意。

A physically-based distributed watershed water erosion prediction model

A physically-based distributed watershed model for water erosion prediction is established through the combination of distributed hydrological component and soil erosion/sediment transport component.Based on the digital elevation model(DEM),the watershed is generalized as a system composed of hillslopes and river channels,then the channels are organized as river networks by "+1" classification method which realizes the model’s parallel computing.The hillslope unit includes four layers,vegetation layer,surface layer,unsaturated zone and groundwater layer.The processes of rainfall,interception,evapotranspiration,infiltration,surface runoff,subsurface flow,groundwater,and various forms of erosion and sediment transport are simulated.Flow convergence and sediment transport are simulated in the river channels.The simulation result of long series of rainfall in the Lizixi watershed,Sichuan Province,shows that the accuracy of the hydrological component is good and that of soil erosion component is acceptable.