流域汇流的非线性关系及其处理方法

NONLINEAR RELATIONSHIPS OF CONCENTRATION FOR A WATERSHED AND A METHOD OF DEALING WITH THEM

本文简要回顾了国内外有关流域降雨径流非线性关系的研究情况;根据笔者参加的西北地区坡面流试验(11组316场)与室内模拟实验(2组234场)的资料分析,进一步论证了流域汇流的非线性问题,初步探讨了非线性指数与流域特征值的关系;在此基础上,本文提出一种非线性处理方法,可供流域汇流计算参考使用。

The paper briefly reviews the research work on nonlinear relationships between rainfall and runoff for a watershed at home and abroad. According to experimental data of overland flow on field in northwest regions of China and those of channel and laboratory watershed in the laboratory,there are H groups that consist of 316 events on field and 2 groups that consist of 234 events in laboratary. Nonlinear relationships are further proved and the relationships between the index of nonlinearity and characteristics of watershed are preliminarily analysed, the mathematical formula of which is as follows. βS = 0.6614exp(-1.54i1/3A2) for overland flow on field, U1’,r=31 .0Ir-0.342Tr-0-177 for channel flow on laboratory, and UJ1’=218.4 I-0.82T-0.57 for watershed on laboratory, in which βS-the index of nonlinearity ;i-overland slope (%);A2-the coefficient for the convectivc speed of flow path on overland; U1’,r-the time of lag for channel (s) ; Ir-intensity of inflow (1/s) ; Tr-period of inflow (s) ;U1’-the time of lag for laboratory watershed (s) ; I-intensity of effective rainfall(1/s) ; T-period of effective rainfall (s) .On the basis of this, a method which deals with nonlinear relationships of concentration for watershed has been put forward in the paper.