近55年来降水及人类活动对沅水流域径流的影响

Impact of Precipitation and Human Activities on Runoff in Yuanshui River Basin in Recent 55 Years

[目的]开展降水和人类活动对沅水流域径流影响的定量研究及其成因分析,为该流域水资源开发利用提供科学依据。[方法]采用累计距平法以及滑动t检验法对沅水流域近55 a的降水量、径流量序列进行趋势分析和突变检验,采用双累积曲线法分别计算降水及人类活动对沅水流域径流量变化的贡献率。[结果]除安江站受人类活动影响较明显,其贡献量为60%外,在变异期Ⅰ(1989—2003年),降水对流域径流的影响量大于人类活动的贡献率;在变异期Ⅱ(2004—2014年),人类活动的贡献率大幅增加并逐步成为径流变化的主要驱动因素。[结论]近55 a来,人类活动因素对沅水流域径流量的影响不断增加,沅水流域下游受人类活动的影响贡献率的增幅最大。

[Objective]The impacts of precipitation and human activities on runoff in Yuanshui River Basin and its cause were studied in order to provide scientific basis for the water utilization of Yuanshui River basin.[Methods]By using cumulative anomaly method and sliding t test,the trend and mutation test of precipitation and runoff series in recent 55 years in Yuanshui basin were carried out.The contribution rate of precipitation and human activities to runoff change in Yuanshui River basin was calculated by double cumulative curve method.[Results]In addition to Anjiang Station,which was obviously influenced by human activities,its contribution was 60%.In the period of variationⅠ(1989—2003),precipitation had greater impact on runoff than the contribution rate of human activities.In the period of variationⅡ(2004—2014),the contribution rate of human activities increased significantly and gradually became the main driving factor of runoff change.[Conclusion]In recent 55 years,the influence of human activities on runoff in the Yuanshui River basin had been increasing.The contribution rate of human activities in the lower reaches of the Yuan River basin had increased the most.