淮河流域径流时空变化特征分析

基于淮河流域主要干支流26个水文站点1956-2008年的实测径流资料,针对不同时间尺度,采用Mann-Kendall、Sequential Mann-Kendall和Distribution-free CUSUM等多种非参数检验方法对径流年际变化的趋势性和突变性进行分析。结果表明:流域径流年际变化趋势存在一定空间差异,除上游区表现出不显著的上升趋势外,大部分地区呈现出下降趋势,其中淮河水系中游以北地区与沂沭泗水系表现出显著的下降趋势;淮河水系径流量在春季(尤其4-5月份)表现出最大范围的下降趋势,在夏季(尤其7-8月份)呈现出以上升趋势为主的变化趋势,径流量年内分布不均匀化将进一步加大,可能加剧地区水资源供需矛盾和旱涝灾害;沂沭泗水系径流量在夏季表现出最大范围的下降趋势,7月份径流量的趋势值中值最小,达到了95%的显著水平;受到强烈的人类活动影响,流域年径流突变年份存在一定的时空差异,总体主要发生在20世纪70、80年代。

Spatial temporal variability of streamflow in Huaihe River

This study is based on the measured streamflow data from 1956-2008 from 26 hydrometric stations across Huaihe River Basin (HRB) . The Mann-Kendall, Sequential Mann-Kendall and distribution-free CUSUM tests were employed to detect the trends of streamflow and the abrupt change points of annual streamflow at different spatial scales. The results showed that: except in the headwater catchment of the basin with an insignificant increasing trend, the annual streamflow decreased across the basin, especially in the mainstreams of the northeast part of the Huaihe River System (HRS) and the Yishusi River System (YRS); most stations in the HRS showed decreasing streamflow in spring (i.e. April to May) and rising streamflow in summer (i.e. July and August), indicating that drought and flood in the HRS could be more serious; the decreasing streamflow trend in summer was the strongest as compared to other seasons in the YRS, and the streamflow in July reached the lowest, with 95% significant level. affected by strong human activities, the change points of annual streamflow was relatively complex and shows spatial and temporal variability, wich mainly happened between 1980~1990.