中国主要江河径流变化成因定量分析

变化环境下中国主要江河实测径流量发生了较为明显的变化，科学理清径流变化原因是流域水资源评价和管理的重要基础工作。基于中国七大江河代表性水文站1956—2018年的实测径流量资料，诊断了变化环境下水文序列的变异性特征；采用水文模拟途径，定量评估了不同驱动要素对径流变化的影响。结果表明：①淮河、长江和珠江实测径流量变异性特征不明显，相比而言，北方主要江河实测年径流量系列存在较为明显的突变性，但最显著的变异点发生时间存在差异，变异前后降水径流关系发生较大变化。② RCCC-WBM模型能够较好模拟中国南方湿润区和北方干旱区江河天然径流量过程，该模型可以用来还原人类活动影响期间的天然径流量。③总体来看，人类活动对中国北方江河径流量的影响大于气候变化的影响，气候变化是中国淮河及其以南江河径流变化的主要原因。

Quantifying attribution of runoff change for major rivers in China

The recorded runoff of the major rivers in China has been changing due to environment change. It is of significance to quantitatively analyze attribution of runoff change for supporting water resources assessment and management in many practices. Based on abrupt change detection of annual runoff series from 1956—2018 measured at the 8 representative hydrometric stations on major rivers in China,impacts of climate change and human activities on runoff changes were investigated by using hydrological simulation approach. Results show that (1) The abrupt change of annual runoff series recorded at the Wujiadu station on the Huai River,Datong station on the Yangtze River and the Wuzhou staion on the Pearl River are not detectable. However,the abrupt changes have been found for the recorded annual runoff series of the major rivers in North China with the earliest and the latest abrupt change years occurring in 1965 for the Tieling station on the Liao River and in 2003 for the Haerbin station on the Songhua River,respectively. The relationships between runoff and precipitation for periods before and after abrupt change year were markedly changed probably due to human activities. (2) RCCC-WBM model not only performs well on monthly runoff simulation for humid South China,but also achieves good simulation result for major rivers in arid North China. The model has been proved being qualified to naturalize runoff in the human-disturbed periods for major rivers in China. (3) In general,human-induced runoff changes are higher than the climatic impacts for major rivers in the North China,while climate change is a dominant driver of runoff variation for the Hai River and major rivers of China in its south.