三峡工程蓄水后沙市水文站水文要素特性分析

Analysis on the Characteristics of Hydrological Elements in Shashi Hydrological Station after Three Gorges Reservoir Impounded

三峡工程蓄水后,清水下泄,坝下河段水沙特性出现明显变化。本文利用沙市水文站1991年~2021年实测资料,系统分析了蓄水前后测站水位、径流量、悬移质输沙率等水文要素的变化情况。结果表明,三峡工程蓄水后,沙市水文站多年平均水位下降0.95 m,多年平均径流量变化不大,但汛期径流量减少8.5%,而非汛期径流量增加18.5%,多年平均含沙量、多年平均输沙量分别减少85.5%、85.8%,流量测验断面形态保持稳定,但是冲刷明显,2003~2021年左侧深泓(代表垂线200 m)冲深7.7 m,右侧边滩(代表垂线900 m)冲深4.0 m。研究成果可以为测验方式方法创新、河道治理、防洪规划等提供参考。

After the Three Gorges Reservoir (TGR) impounded, the water and sand characteristics of the river section under the dam have changed significantly due to the release of clear water. This paper uses the measured data of Shashi Hydrological Station (SHS) from 1991 to 2021 to systematically analyze the changes of hydrological elements such as water level, runoff, and sediment transport rate at the sta-tion before and after impoundment. The results show that after the impoundment of the TGR, the mul-ti-year average water level of the SHS decreased by 0.95 m, and the multi-year average runoff did not change much. The multi-year average sediment concentration and sediment transport decreased by 85.5% and 85.8% respectively. The flow test section shape remains stable, but the erosion is obvious. From 2003 to 2021, the deep shoal on the left (representing the vertical line of 200 m) is 7.7 m deep, and for the right side beach (representing the vertical line of 900 m), the drawing depth is 4.0 m. The research results can provide reference for the innovation of testing methods, river management, flood control planning, etc.