【摘要】 泥沙及污染物质在自然界搬运、输移,主要依靠运动水流冲刷、挟带来完成.在坡面上一场降雨以薄层漫流形式汇集到沟壑,其流量集中,单位水体侵蚀、挟沙能力迅速增大.本文为了描述象这样的黄土地区径流形成过程中两种不同形式,首先将流域分为面蚀区和重力侵蚀区,然后直接应用干旱地区流域水文模型计算的净雨过程覆盖在坡面面蚀区域上,建立了在坡面层状漫流过程中它所形成的泥沙层状剥蚀、推移质运动方程以及地表流汇集到沟壑河网后,穿过重力侵蚀区的沟蚀悬移质运动方程.本文在这里指出流域产沙主要是由这两种方式引起的. 最后结合岔巴沟流域产沙计算的例子,本文总结了流域下垫面因素对流域产沙量的影响.更多还原

【Abstract】 Sediment and contaminant, during moving and migrating process in nature, mainly depend on moving flow fully to wash and carry it. A rainfall on the slop flow together into the ditch in a layer of thin overflow. The discharge of that enlarges the capacity of erosion and sandment-laden per volume rapidly. In order of to describe two types of the status during runoff process for loess region in this article, first of all, one should divide a basin into surface erosion zone and heavy erosion zone, and apply directly to the net rainfall process caculated by hydrological basin model for arid region, covering on the slop of surface erosion zone, and set up the surface erosion equation of bed load transport in which sediment are eroded in stratificate status during laminar overflow process on the slop and the diteh erosion equation of suspended load transport gone through heavy erosion zone during runoff process in the ditch and river system. This paper presents the viewpoint that sediment yield ofabasin is mainly caused by the modl of these two kinds.Finally, combining the caeulating example of sediment yielded from Cha Ba Gou basin, this paper summarizes the effect of the basin geographic elements to sediment yield of the basin.更多还原