黄河数字流域模型的建立和应用

黄河数字流域模型是“数字黄河”的重要组成部分,在数字流域模型框架下,以坡面为基本单元,建立了包括植被截留、融雪、地表蓄滞、表层土蓄滞、中层土蓄滞和深层土蓄滞共6层的产流模型.模型在垂向上考虑3层出流:地表超渗产流、表层土侧向渗流和中层土侧向渗流,既反映当前的降水过程,又体现前期降水过程和土壤前期含水量的影响,比较适合黄河流域的产流特点.在坡面产流的基础上,还给出了坡面单元侵蚀产沙公式,用于建立流域产沙数学模型.应用建立的模型,给出了3个计算实例:黄河全流域水量计算、小花区间汛期洪水模拟和多沙粗沙区产沙计算.实践表明:建立的模型基本具备了在黄河全流域进行降雨-径流模拟、侵蚀产沙计算的功能,辅以降雨预报模块则可进行洪水预报.

Digital watershed model for the Yellow River: construction and application

The digital watershed model for Yellow River is the main part of the "Digital Yellow River" Project.The digital watershed model of Yellow River is developed based on the hillslope unit,under the former constructed framework,which consists of six layers: the canopy storage,the snow storage,the surface storage,the top-soil storage,the middle-soil storage and the deep-soil storage.Three kinds of runoff are considered from the ground surface to middle soil: the overland flow for fast runoff,the interflow from the top soil and that from the middle one for slow runoff.The fast runoff is the response to the current precipitation,and the slow runoff reflects the influence of former precipitation,which is very important for rain-runoff simulation in the Yellow River basin.In addition,a soil-erosion formulation is proposed for the sediment yield simulation.The suggest model is applied in three cases: the computation of the water resources in the Yellow River basin,the rain-runoff simulation in Xiaolangdi-Huayuankou area,the soil-erosion simulation in the sandy and grit area in the Loess Plateau.The well-fitted results indicate that the model would have a good prospect of application in the future.