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在已建立的黄土坡面细沟侵蚀CA模型基础上,侧重研究不同元胞大小对坡面细沟发育过程和细沟特征参数的影响。通过累积径流量和累积侵蚀量的Nash-Sutcliffe系数Ens和误差系数Re,分析元胞大小对CA模型有效性的影响。当保持模型其他参数和运行时间都不变时,元胞尺寸增大,细沟发育过程加速,细沟平均沟宽变宽,沟长变长,坡面径流和产沙的趋势提前,同时累积径流量减小,累积侵蚀量增加;当元胞尺寸变小时则相反。由于CA模型的流速是由元胞边长和时间步长的比值来决定的,所以只有其与实验坡面流速接近时才能提高模型的有效性。
On the basis of established CA model of rill erosion on loess slope, the effects of different cell sizes on the development of rill and the characteristic parameters of rill are discussed. The effect of cell size on the validity of CA model was analyzed by accumulating Nash-Sutcliffe coefficient Ens and error coefficient Re of runoff and cumulative erosion. When keeping the other parameters of the model and running time unchanged, the cell size increased, the development of the rill was accelerated, the average width of the groove increased, the length of the groove increased, the trend of runoff and sediment yield ahead of time, The runoff decreases, and the cumulative erosion increases. When the cell size becomes smaller, the opposite is true. Since the flow rate of the CA model is determined by the ratio of the cell edge length to the time step, the effectiveness of the model can only be improved if it is close to the experimental slope flow rate.