渭河流域径流年内分配变化规律分析

Analysis on the Variation Law of Annual Runoff Distribution in the Weihe Basin

在气候变化以及人类活动的影响下,河川径流的年内分配特征发生着相应的变化,直接影响水资源的开发利用以及生态系统的健康。以渭河流域上游北道站、中游咸阳站和下游华县站40多年的实测月径流资料为基础,研究了渭河流域径流年内分配的变化规律。通过计算径流年内分配不均匀性、集中程度、变化幅度等指标发现,渭河流域径流量具有显著的洪枯季节变化;20世纪90年代的径流年内分配特征出现了较大的变化,突出表现在汛期径流量的减少;径流年内分配的多项指标显示,渭河下游华县站的不均匀性、集中度及变化幅度均高于上中游的北道站和咸阳站。

With the impact of climate change and the increasing intensity of human activities,the hydrological regime has changed,including annual runoff distribution,which is related with water resources management and ecological construction.Based on the monthly runoff data for more than 40 years of the Beidao,Xianyang,Huaxian station on Weihe Basin,the annual distribution characteristics of runoff were studied.Several indices related to attributes of uneven,concentrate degree and variation amplitude were calculated,and the results showed that there have obvious fresh and drought seasonal changes in 1990s,the annual runoff distribution had changed a lot,mainly because of runoff decrease in the wet season;The Huaxian station,which locates at the upper reaches,has a higher unevenness,concentration and relative variation rate than that of the Beidao and Xianyang station.