确定侵蚀细沟集中水流剥离速率的解析方法

ANALYTIC METHOD FOR DETERMINATION OF DETACHMENT RATE OF CONCENTRATED FLOW IN EROSION RILLS

细沟中的泥沙主要来源于细沟流对土壤的剥蚀作用 ,细沟剥蚀作用的大小由剥蚀率来表述。剥蚀率是侵蚀过程预报模型的重要物理参数 ,本文创造性提出了一种确定侵蚀细沟集中水流剥离速率的解析方法。该方法用细沟侵蚀模拟试验所确定的沟长与水流载沙量的函数关系 ,以及相应的回归参数 ,通过将函数对距离求导数 ,得到了水流的剥离速率与细沟长度的函数关系。由此 ,进一步确定了剥离速率与水流载沙量的函数关系。将由解析法得到的剥离速率与由试验数据直接计算得到的结果进行了对比 ,得到不同坡度的确定系数下R2 值最小为 0 .65(坡度为 5) ,n=1 6 ,最好的拟合R2 值 0 .96(坡度为 2 0°) ,n =2 4 ,证明了该解析方法的可行性。

An analytic method for determining detachment rate of concentrated flow in erosion rills was advanced in the paper.By making use of the functional relation of sediment load with rill length and the corresponding regression parameters obtained from simulated erosion experiments this method estimated functional relations of detachment rates of concentrated flows with rill length.Then relationship between detachment rate and sediment load in the flowing water was derived from this function.Comparison of the detachment rates thus computed with those directly estimated on the basis of experimental data was conducted to prove feasibility of this method.