长江重庆主城区河段水沙变化特征分析

Analysis of variation characteristics for runoff and suspended load runoff in Chongqing reach of the Yangtze River

在自然因素和人类活动的综合作用下,近期(2000年后)长江重庆主城区河段的水沙特性发生了一定变化。基于长江寸滩站、朱沱站和嘉陵江北碚站(简称"三站")1955-2011年的流量和悬移质含沙量资料,分析了长江重庆主城区河段的水沙变化特征,结果表明:径流量和输沙量主要集中在汛期,年内分配具有高度集中和极不均匀的特点;径流量和输沙量年际交替变化,水沙阶段变化过程总体具有同步性,且均表现为长程正相关;与2000年前相比,三站近期的年均径流量分别减少了5.4%、5.0%和8.0%,年均输沙量分别减少了62.1%、44.3%和97.1%;三站年输沙量总体随年径流量呈递增变化,但不同时期的水沙关系差异较大。

By integrated influences of natural and human activities, the runoff and suspended sediment runoff （SSR） characteristics in Chongqing reach of the Yangtze River have changed over the recent years （after 2000）. Based on the daily flow and suspended sediment concentration data of three hydrological stations at Cuntan, Zhutuo and Beibei （referred to as ＂the three stations＂） in 1955 -2011 years, the variation characteristics of runoff and SSR were analyzed. Result shows that： The runoff and SSR of the three stations are mainly concentrated in the flood season, and the annual distribution is highly concentrated and extremely uneven ; Runoff and SSR display inter-annual alternations, the variation processes of different times has some synchronization, and show positive correlation of long period ; Compared with that before the year of 2000, the recent average annual runoff of the three stations have decreased by 5.4% , 5.0% and 8.0% respectively, the average annual SSR were reduced by 62. 1% , 44. 3% and 97.1% ; The annual SSR generally increases with runoff, but the relationships are obviously different among different periods.