金沙江流域径流特性变化及影响分析

Analysis of Runoff Characteristic Change and Influence on Jinsha River Basin

以金沙江流域屏山站55 a(1950～2004)水文资料为基础,研究了流域内径流的变化特征。运用多种统计方法较系统地分析了屏山站径流的年内、年际变化规律及影响流域径流变化的因素。结果表明,流域径流年内分配不均匀系数Cvy的值介于0.05～1.49之间,且有减少趋势。径流的年际变化剧烈,丰水时段与枯水时段交替出现,由年降水—径流双累积曲线及回归分析可知,降水是影响流域径流变化的主要因素,人类活动对径流变化影响较小。

The characteristic about runoff change within the river basin are researched in the study according to the hydrologic data on Pingshan station existing on the Jinsha river basin in 55 years from 1950 to 2004. Various statistical methods are ap- plied to analyze systematically the yearly and interannual changing law of Pingshan station runoff and the factors affecting river basin runoff change. The results show that the annual uneven distribution coefficient value of river basin runoff is between 0.05 and 1.49, and is in the tendency on decreasing. The annual change of runoff is severe and the rainy period and low - water period take place by turn, based on the precipitation--runoff double accumulation curves and regression analysis, it is known that precipitation is the major factor affecting runoff change and the influence of human activity on runoff change is less.