三峡库区土脑子河段冲淤特性分析

Analysis of Aggradation and Degradation of Tunaozi Reach in Three Gorges Reservoir Area

土脑子河段处在三峡工程135m运行水位的变动回水区,天然情况下具有汛期淤积、汛末及汛后冲刷、年内冲淤平衡的规律。三峡工程蓄水以来,河段洲滩、岸线无明显变化,河床冲淤主要集中在右侧主槽土脑子一带。由于汛期淤沙在汛末、汛后及次年消落期冲刷不足,河段产生了累积性淤积。分析表明,水库调度、来水来沙、河床形态是影响冲淤变化的主要因素。

The Tunaozi reach, which lies in the 135m fluctuant backwater area of the Three Gorges Project, under natural condition, has the characteristics of aggradation during flood season, scouring in late flood season and after flood season and balanced aggradation and scouring in a year. Since the Three Gorges reservoir begarrto store water, the fiver bank of the reach has not changed clearly and the river bed scour has been discovered mainly on the fight trough. Because of the sediment during the flood season and the uneven scour after flood season and the following year, accumulated sediment arises. Analysis shows that the adjustment of the reservoir, the coming water and sand, and the form of the fiver bed are the main factors of sediment change.