金沙江上游水能资源丰富,规划开发13个梯级电站,河道水文泥沙情势及其变化对电站建设、调度运行有重要的影响。以金沙江上游岗拖、巴塘和石鼓水文站1971—2020年实测水文泥沙资料为基础,分析了近50 a金沙江上游水沙变化特性。结果表明:金沙江上游年际径流量和输沙量均呈现一定的增加趋势,且输沙量增幅较径流量明显偏大,水沙相关关系和双累积曲线关系都在发生变化;年内汛期径流量占比较为稳定,输沙汛期集中的现象更为明显,受2018年白格大型滑坡事件的影响,2011—2020年的10、11月份输沙量占比较以往有所提高;导致金沙江上游水沙变化的主要因素有降雨变化、大型滑坡事件和人类活动等,2018年的白格滑坡和堰塞湖事件导致该年和2020大水年输沙量较近50 a均值偏大91.7%~148%。

Endowed with abundant hydropower resources,the upstream of Jinsha River is going to witness thirteen cascade hydropower stations in planning.The hydrological and sediment situation and its changes will have significant impact on the construction,dispatching and operation of the hydropower stations.In this paper,the variations of water and sediment in the upper Jinsha River in recent five decades are examined according to measured hydrological and sediment data of Gangtuo,Batang and Shigu hydrological stations.Results unveiled that the interannual runoff and sediment discharge in the upper Jinsha River presented increasing trend,and the increase of sediment discharge was obviously larger than that of runoff.In the meantime,the correlation between water and sediment and the double accumulation curve were both changing.The proportion of runoff in flood season was relatively stable during the year,and the concentration of sediment discharge in flood season was more obvious.Affected by the Baige large landslide in 2018,the proportion of sediment discharge in October and November,2011-2020,was higher than that in the past.The main factors leading to the changes of water and sediment in the upper Jinsha River include rainfall changes,large-scale landslide events and human activities.The Baige landslide and the following barrier lake led to a 91.7%-148% increase in sediment discharge in 2018 and 2020 compared with the average value in recent five decades.