Low公式计算坡面流挟沙力的改进

Improvement of Low Formula for Calculating the Sediment Carrying Capacity of Overland Flow

坡面流的挟沙能力决定着坡面土壤是否发生侵蚀或者淤积,其计算是坡面侵蚀产沙模型开发的关键。将Low公式应用于一维坡面侵蚀产沙模型,基于径流小区实测资料修正坡度项的指数对公式提出改进。结果表明:随着坡度指数的增加,侵蚀量的模拟误差先减小后增大,存在一个临界值,使模拟误差达到最小;建议Low公式应用于坡面侵蚀产沙模型时坡度项的指数取值为0.453。

Sediment carrying capacity of overland flow decides whether the erosion or deposition happens on the slope,and it is the key point to the development of slope erosion model.The Low equation is applied in a one-D slope erosion model,and is improved by modifying the gradient index based on the measured data of a runoff plot.Results show that,with the increase of gradient index,the simulation error of soil erosion decreases first,and reaches a minimum value,then increases.A gradient index value of 0.453 is suggested for Low equation when applied in slope erosion model.