金沙江下游水沙序列变异诊断及归因分析

Variation Diagnosis and Attribution Analysis of Flow and Sediment Sequences in the Lower Reaches of Jinsha River

摘要: 金沙江中下游干流、支流雅砻江梯级水电站相继建成运行，使得进入金沙江下游水沙特性出现了一些新变化。本文采用水文变异诊断系统对金沙江下游干流关键控制站的年径流量、年输沙量序列进行了变异诊断及归因分析。主要结果为，金沙江下游水沙关系发生明显变化，主要体现在径流量总体变化不大，但输沙量明显减少。石鼓、白鹤滩、向家坝站年径流量序列未发生变异，受面平均降水突变式跃升的影响，攀枝花站年径流量序列在1997年发生向上的跳跃变异。因极端降水增加致使产沙变大，石鼓站年输沙量在1997年发生向上的跳跃变异；因金沙江中游水库建设的影响，攀枝花、向家坝站年输沙量在2010年发生向下的跳跃变异；因攀枝花至华弹区间年输沙量显著减少，白鹤滩站年输沙量在2002年发生向下的跳跃变异。

Abstract: The cascade hydropower station in the middle and lower reaches of the Jinsha River and tributary Ya-long River has been completed and put into operation, which has brought some new changes in the characteristics of flow and sediment entering the lower reaches of the Jinsha River. In this paper, the variation diagnosis and attribution analysis of the series of annual runoff and annual sediment load of key control stations in the lower reaches of the Jinsha River were carried out using the hydrological variation diagnosis method. The main results are that the relationship between flow and sediment in the lower reaches of the Jinsha River has changed significantly, which is mainly reflected in the fact that the overall change in runoff is not large, but the amount of sediment load is significantly reduced. The annual runoff sequence of Shigu, Baihetan, and Xiangjiaba stations did not change, but the annual runoff sequence of Panzhihua station jumped upward in 1997 due to the sudden jump in average precipitation. Due to the increase of extreme precipitation, the sediment production increased, and the annual sediment load at Shigu station jumped upward in 1997. Due to the influence of the construction of the reservoirs in the middle reaches of the Jinsha River, the annual sediment load of Panzhihua and Xiangjiaba stations experienced a downward jump variation in 2010. Due to the significant decrease in the annual sediment production from Panzhihua to Huatan, the annual sediment load at Baihetan station jumped downward in 2002.