黄土区细沟侵蚀过程中输沙能力确定的解析法

An Analytic Method for Determining Transport Capacity of Concentrated Flow in Eroding Rills

输沙能力是坡面细沟侵蚀过程预报模型中所需的重要参数,确定坡面输沙能力一直是土壤侵蚀研究关注的问题。解析法是用数学上的积分和积分变换等方法直接求数学模型的解,其优点是把表征坡面土壤运动规律的变量和时空变化包含在一个表达式内,可以分析土壤侵蚀的过程运动规律。由细沟侵蚀室内模拟试验得出的剥蚀率和含沙量之间的函数关系,推导得到了计算细沟输沙能力的解析式。将由解析方法计算求得的水流输沙能力与由试验数据直接估算出来的结果进行了对比,验证了该解析式的合理性。

Prediction of sediment transport capacity in eroding rills is of great importance to the development of theprocess-based water erosion prediction model. The difficulty to determine sediment transport capacity limits the modelvalidation and application. The analytic method includes the temporal and spatial variables in one function so as to analyzethe mechanics of eroding rill processes. With an analytic method, transport capacity of concentrated flow in eroding rills onloess slope was derived from the functional relation of detachment rate with sediment load. Sediment transport capacitiesestimated with this proposed analytical algorithm were compared with those determined by the empirical expression, whichfurther verified the feasibility of the method. The analytic method is helpful to compute the parameters of the models andwould be a powerful tool for the complete validation of the process-based models.