【摘要】 运用小波变换的方法研究了长江流域干流站(屏山站、宜昌站、大通站与汉口站)以及位于支流嘉陵江流域的北碚站近40年来月均流量与输沙率,研究认为:(1)水利工程(本文主要指水库)对下游河道输沙率的影响远远大于对流量的影响;(2)葛洲坝是低水头径流式发电站,对下游流量变化影响不大,虽然在建库初期对输沙率有一定影响,导致下游河床下切,但远未达到使输沙率固有的1年周期受到影响的程度;(3)三峡大坝的建设已经对下游输沙率产生严重影响,使其固有的1年周期消失,但三峡大坝下游河道输沙率对这种影响的响应与距三峡大坝的距离成反比,即愈往下游,输沙率受三峡大坝的影响愈小;(4)输沙率变化对水利工程影响的敏感程度受流域尺度的影响,流域尺度越大,其反应就愈迟钝,反之亦然。更多还原

【Abstract】 Monthly mean sediment load and runoff changes in the past 40 years are analyzed at Pingshan station,Yichang station,Datong station and Hankou station along the mainstream of the Yangtze River basin and Beipei station in the tributary of the Yangtze River basin,with the help of wavelet transform method.The results indicate that:① the wavelet transform method is the proper method for detecting the influences of water reservoirs on transportation of sediment load and runoff changes.The influences of water reservoirs on sediment load are more serious that those on runoff changes;② Gezhouba dam exerts less influences on runoff changes and sediment load.The down-cut of the riverbed occurrs after the operation of Gezhouba dam,but this influences are not enough to remove the 1-year-period of runoff and sediment load changes;③ The Three Gorges dam exerts increasing influences on sediment load transportation,removing the 1-year-period sediment load of sediment load changes,but shows no influences on runoff changes.The influences of Three Gorges dam on sediment load are adverse to the distance to the Three Gorges dam;④ The influences of water reservoirs on sediment load and runoff changes is related to the size of the river catchment.The sensitivity of influences of water reservoirs on sediment load is less in the larger river catchment.更多还原