自然降雨条件下不同生态措施坡地的径流数值模拟

Numerical Simulation of Runoff Generation on Slope under Different Ecological Measures for Natural Rainfall

从动量定理和水量平衡原理出发,以Saint Venant方程为基础推导出自然降雨条件下不同生态措施(即同时考虑变雨强、降雨动量和不同生态措施影响下的坡地径流过程)坡地的径流基本方程。在考虑一般问题定解条件的基础上,采用Preissmann隐式格式对模型进行数值求解。利用3个处理(裸地、百喜草覆盖和百喜草+果树覆盖)、5组实测资料(不同雨型)对模型进行了验证,结果表明3个处理的计算值与实测值的平均相对误差分别为:14.97%、13.59%、15.15%,说明模型的计算结果是可靠的,对于模拟预测自然降雨条件下不同生态措施坡地径流过程是可行的。

Based on the principle of momentum theorem and water balance the basic equation for describing the runoff generated on a slope under the condition of natural rainfall with different rainfall intensities, rainfall momen- tum and influence of ecological measures taken into account is deduced. The equation can be numerically solved by applying the Preissmann format. The feasibility and precision of the model is verified by field experimental data. Results show that the mean relative errors of the prediction under 3 treatments are 14. 97%, 13.59% and 15.15%. The model is quite high in accuracy and stability, and serves as useful tool in further research on predic- tion of runoff of nature rainfall on slopes under different ecological measures.