基于新安江模型的老挝南俄河流域径流变化贡献率分析

Analysis of contribution rate of runoff variability of Nam Ngum River Basin in Laos based on Xin’anjiang model

为分析20世纪60年代以来气候变化和人类活动对老挝南俄河流域径流变化的贡献率,基于流域内地面站点实测降水数据,对广泛应用于湄公河流域的APHRODITE和MSWEP两种卫星降水产品日降水数据进行了偏差校正,采用经校正的基准期卫星日降水和白冠洪、欣赫普两站点实测日径流资料构建了新安江模型,模拟还原了流域水库影响期的天然日径流过程,定量分析了气候变化和人类活动对径流变化的贡献率。结果表明:南俄河流域年径流总体呈下降趋势;白冠洪站两个水库影响期气候变化对径流变化的贡献率分别为-429%和-399%,欣赫普站水库影响期气候变化对径流变化的贡献率为-380%,而对应的人类活动贡献率分别为529%、499%和480%,人类活动是流域径流变化的主要原因;以水库运行为主的人类活动对径流年内分配影响显著,丰水期人类活动影响量的绝对值超过气候变化影响量绝对值的2倍。

In order to analyze the contribution rate of runoff variability from climate change and human activities in the Nam Ngum River Basin in Laos since the 1960s,the daily precipitation data from two widely used satellite precipitation products in the Mekong River Basin,APHRODITE and MSWEP,were bias-corrected based on the measured precipitation data from ground stations in the basin.The Xin’anjiang model was constructed using corrected satellite daily precipitation and measured daily runoff data from Pakkanhoung and Hinheup stations during reference period,and the natural daily runoff process in the basin during reservoir influence periods was simulated.The contribution rate of climate change and human activities to runoff variability was quantified.The results show that there is a general downward trend in annual runoff in the Nam Ngum River Basin.The contribution rates of climate change to the runoff variability during the two reservoir influence periods were-429%and-399%at the Pakkanhoung station,respectively,and the contribution rate was-380%at the Hinheup station.The corresponding anthropogenic contribution rates were 529%,499%and 480%,respectively.Anthropogenic activities are the main cause of runoff variability in the basin.Anthropogenic activities mainly based on reservoir operation,have a significant imp.