基于改进径流曲线数模型的北京密云坡地径流估算

发布时间：2018-06-16 05:47

  本文选题：径流 + 模型　； 参考：《农业工程学报》2017年21期

【摘要】：密云区是北京重要的地表饮用水源地,准确模拟地表径流量,对于分析泥沙和污染物的运移十分重要。近年来,学者们运用径流曲线数(soil conservation service curve number,SCS-CN)模型计算本区地表径流量,但预报精度不理想;未考虑降雨过程和雨强对于产流过程的影响,可能是造成预报误差的重要原因。该文利用密云石匣小流域5个坡面径流小区共201场降雨产流资料,提出次产流径流曲线数计算方法,以改进SCS-CN模型并分析改进后模型模拟效果。结果表明,次产流径流曲线数与多年平均径流曲线数的比值和最大30 min降雨量与次雨量的比值之间呈显著幂函数递增关系,据此提出计算次产流径流曲线数的幂函数方程,以改进SCS-CN模型。当曲线数为0.02时,改进后模型模拟效果最好,效率系数为0.693,明显高于未改进的SCS-CN模型。改进后模型对裸地和耕地的产流模拟效果较好,但对林地的产流模拟效果不理想。今后需在深入分析产流机理的基础上,进一步提出与土壤特性有关的模型参数优化方法。
[Abstract]:Miyun area is an important source of surface drinking water in Beijing. It is very important to simulate the surface runoff accurately for analyzing the transport of sediment and pollutants. In recent years, the surface runoff in this area has been calculated by soil conservation service curve number-SCS-CNC model, but the prediction accuracy is not ideal, and the influence of rainfall process and rain intensity on runoff production process may be the important reason for the forecast error. Based on 201 rainfall runoff data from five slope runoff plots in Miyun Shixia small watershed, this paper presents a method to calculate the number of secondary runoff curves in order to improve the SCS-CN model and analyze the simulation effect of the improved model. The results show that the ratio of the number of secondary runoff curves to the number of annual average runoff curves and the ratio of maximum rainfall of 30 min to the ratio of secondary rainfall are significantly increased by power function. Based on this, the power function equation for calculating the number of secondary runoff curves is proposed. To improve the SCS-CN model. When the curve number is 0.02, the simulation effect of the improved model is the best and the efficiency coefficient is 0.693, which is obviously higher than that of the unimproved SCS-CN model. The improved model can simulate the runoff yield of bare land and cultivated land better than that of forestland. On the basis of deeply analyzing the mechanism of runoff production, the optimization method of model parameters related to soil characteristics should be put forward in the future.
【作者单位】： 中国水利水电科学研究院;北京市密云区水土保持工作站;
【基金】：国家自然科学基金项目(41401560)
【分类号】：S157
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本文编号：2025601