摘要
为了分析2018年汛期三峡水库入库沙量集中,7月入库沙量比蓄水以来同期大幅偏多的原因,对2018年汛期三峡上游暴雨产沙特性进行了深入分析研究。分析结果表明:2018年7月嘉陵江和岷沱江流域发生强降雨,由于嘉陵江上游支流西汉水、白龙江中游、岷江等流域均属于强产沙地区,受暴雨洪水影响,流域侵蚀量大,增加了三峡入库沙量;降雨带主要沿龙门山断裂带呈带状分布,与汶川地震、芦山地震、九寨沟地震等区域高度重合,诱发大量滑坡和泥石流,再加上地震后坡面土体变松散,更易发生侵蚀,沱江、涪江、白龙江等河流来沙量大幅度增加;三峡水库上游低水头水电工程淤积严重,拦沙能力较小,一些大中型水库前期淤积严重,拦沙能力减弱,导致大量泥沙进入三峡库区。
In order to explain the concentrated entering sediment to the Three Gorges Reservoir during the flood season of 2018 and the significantly large amount of sediment in July 2018 compared with the same period since the Three Gorges Reservoir impoundment,the sediment yield characteristics under the heavy rainfall in the upper reaches of the Three Gorges Reservoir were studied.The results showed that heavy rainfall occurred in the Jialing River and Minjiang River basins in July 2018,because of the strong sediment yield in Xihanshui River,Bailongjiang River and Minjiang basins,there was a large amount of erosion due to heavy rainfall and storm-floods,which increased the amount of sediment inflow of the Three Gorges Reservoir.Rainfall belt mainly distributed along Longmenshan fault zone,which highly coincided with the site of Wenchuan earthquake,Lushan earthquake and Jiuangou earthquake,thus the rainfall belt induced numbers of landslides and debris flows.In addition,the soil on the slope became loose after the earthquake,and more easily to be eroded,so that the amount of sediment inflow from Tuojiang River,Fujiang River and Bailongjiang River increased markedly.Serious deposition occurred in low water head hydroelectric projects with low capability of sediment retention in the upstream of the Three Gorges Reservoir.Also serious deposition had occurred in large and medium reservoirs in history which reduced their capability of sediment retention.Therefore a large amount of sediment were discharged into the Three Gorges Reservoir.
作者
董炳江
张欧阳
许全喜
袁晶
朱玲玲
DONG Bingjiang;ZHANG Ouyang;XU Quanxi;YUAN Jing;ZHU Lingling(Hydrology Bureau,Changjiang Water Resources Commission,Wuhan 430010,China)
出处
《人民长江》
北大核心
2019年第12期21-25,共5页
Yangtze River
基金
国家重点研发计划项目(2017YFC0405301)
三峡后续工作科研项目“未来三峡入库水沙变化趋势研究”(12610100000018J129-01)
中国长江三峡集团有限公司科研项目(0704166)
关键词
暴雨产沙
滑坡
泥石流
水库拦沙
三峡水库
sediment yield under heavy rainfall
landslide
debris flow
reservoir sediment retention
Three Gorges Reservoir
