近60 a河南省河川径流演变特征研究

Evolution of River Runoff in the Henan Province During the Recent 60 Years

河南省地跨海河、黄河、长江、淮河四大流域,水资源问题突出,深入分析河川径流演变规律对河南省水资源管理具有重要意义。选取河南省主要流域的6个代表水文站实测流量数据,利用Mann-Kendall秩次相关检验分析了各代表站年平均流量、月平均流量演变规律。结果表明:近60 a河南省实测流量呈下降趋势,2000年后流量略有回升。自西向东,流量下降速率越来越大。全省径流突变后年平均流量减小,各站减小幅度均大于15%,北部流域突变年份较早,南部流域变化幅度较大。月平均流量总体呈减小态势,海河流域河南段、黄河流域河南段下降显著,达到5%显著性水平。除长江流域河南段外,全省月平均流量年内分配变化不大,从全省范围来看,月径流量占年径流量比例呈枯增丰减态势。

Henan province is located in four major watersheds of the Haihe River,the Yellow River,the Yangtze River and the Huaihe River with a prominent water resources issue.It is of great significance to analyze runoff evolution to water resources management.Characteristics of river runoff variation in the Henan Province were investigated at annual and monthly scales by using recorded runoff gauged at six representative hydrometric stations and the Mann-Kendall rank correlation test method.The results show that the measured stream flow in the Henan Province presentes a decreasing trend over the recent 60 years with a slight increasing after 2000.The linear decreasing rate tends to decrease from west to east.The magnitude of runoff decrease after abrupt change year is over 15%relative to that before mutation year for all six hydrometric stations with earlier abrupt change occurring in the northern rivers and higher change occurring in the southern rivers.The monthly average flow shows an overall trend of decrease,and the Henan section of Haihe River Basin and the Henan section of the Yellow River Basin are decreased significantly,reaching the significance level of 5%.Except for the south section of the Yangtze River Basin,the monthly average flow in the whole province has little change in the annual distribution.