径流曲线数法在黄土高原地表径流量计算中的应用

坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。

Appl ication of Runof f Curve Number Method on Loess Plateau

Overland runoff is the primary force leading to soil erosion. Estimating runoff is a key step to predict the amount of soil and water loss and evaluate the efficiency of soil and water conservation practices. Runoff curve number method, an empirical model to estimate the storm runoff, was developed by USDA SCS. The curve number method is simple and predictable, especially for ungauged catchments. The purpose of this paper is to present the principle of the method, calculate the CN on the basis of data from 25 different ly covered unit plots on the loess plateau, and to analyze the relationship between CN and its relevant factors.At last, the predictive efficiency of the method is assessed.