近 50 年潮河流域降雨-径流关系演变及驱动力分析

潮河流域是北京市城市供水的重要水源地。受环境变化影响, 潮河流域降雨-径流关系发生了显著性变化, 严重影响到北京城市供水安全。利用水文气象长系列数据( 1961- 2014 年) 分析了潮河流域降雨-径流关系的变化, 采用经验统计分析法定量分析气候变化和人类活动对其径流变化的影响, 研究发现: 近 50 年来在降雨波动且微弱下降趋势下, 其径流呈现出较大幅度变化且具有显著下降趋势, 尤其是 2000 年以后; 潮河流域降雨-径流关系发生突变的年份为 1979 年、1998 年。1979 年以后径流系数显著减少, 其中 1979- 1998 年人类活动对径流减少占主导地位, 其影响贡献率为-109.75% , 气候变化对径流影响为正效应, 影响贡献率为 9.75% ; 1999-2014 年人类活动对 径流减少影响贡献率为-88.97% , 气候变化影响贡献率为- 11.03% 。 Chaohe River Basin is an important water source of Beijing . Due to the environmental change, a significant variation occurred to the rainfall-runoff relatio nship of Chaohe River Basin, and this change affected the regional water supply seriously . We analyzed the variation of rainfall-runoff relationship with the long-term hydro-meteorological data (from 1961 to 2014) of Chaohe River Basin, and established an empirical statistical analysis model to analyze quantitatively the impact of climate change and human activity on the runoff condition. The results showed that (1) the runoff changed drastically , and presented a marked dropping trend after 2000, whereas the precipitation showed an insignificant declining trend. (2) The relationship between rainfall and runoff changed abruptly in 1979 and 1998. (3) The runoff coefficient decreased significantly after 1979, and human activity kept a negative effect on runoff, and was always the more dominant factor as compared to climate change. (4) The contribution rate of human activity was -109.75% during 1979 to 1998 and -88.97% during 1999 to 2014, while the contribution rate of climate change was 9.75% during 1979 to 1998 and -11.03% during 1999 to 2014. “十三五”国家重点研发计划项目( 2017YFB0203101) ; 国家自然科学重点基金( 41330529)