乌江干流年径流变化趋势及成因分析

Variation Trend and Driving Factors of Annual Runoff in Wujiang River

以乌江流域3个水文站和80个雨量站实测数据为基础,采用Mann-Kendall法和Kendall-τ关联检验法,对乌江干流年径流的变化趋势进行了分析,并基于降水径流关系初步探讨了其变化的主要原因和贡献率。研究结果表明,20世纪中期至21世纪初乌江河川径流经历了多次丰枯交替的变化过程。通过对降水径流的关联检验得知,乌江径流变化与降水之间关系密切,同时下垫面和人类活动也对年径流量的变化产生了一定的影响。由于乌江流域兴建的水库多为日调节或不完全年调节水库,对径流量年际变化影响相对较小,主要改变的是径流的年内分配过程。

Based on the observed from 3 hydrological stations and 80 rainfall stations in the Wujiang River Basin, Mann-Kendall test and Kendall-τ association test were used to analyze the variation trend of the annual runoff in the Wujiang River, and the factors and contribution rate to the variation were discussed according to the relationship between rainfall and precipitation. The results show that the fiver runoff has several alternate variation processes from the middle 20 century to early 21 century. The association test indicates that there is a close relation between runoff and precipitation, and there is an effect of the underlying surface and human activities on the variation of the annual runoff. Because of daily regulating and incomplete annual regulating operation, the reservoirs in the Wujiang River Basin have more impact on annual runoff distribution than that on interannual variation.