三峡水库蓄水后重庆河段冲淤特性研究

Study on scour and deposition characteristics in Chongqing Reach after Three Gorges Reservoir Operation

三峡水库蓄水对重庆河段冲淤影响的研究具有重要的科学价值和应用前景。根据水沙连续原理和重庆河段输沙特点,考虑嘉陵江汇流和水沙变化特征,导出了重庆河段泥沙淤积比的公式,分析了不同时期河段冲淤变化特点,论证了重庆河段淤积比与嘉陵江汇流比和寸滩站流量有重要关系。三峡水库蓄水初期重庆河段冲淤特点与蓄水前基本一致,具有汛期淤积、非汛期冲刷的特点。试验性蓄水以来河段冲淤特性发生变化,汛后蓄水期和汛前消落期河段有冲有淤,总体发生淤积。汛期河道有冲有淤,淤积有所减轻,甚至发生冲刷。河道采砂对重庆主城区河段冲淤产生重要影响。

Based on the convergent flow ratio of the Jialingjiang River to Yangtze River,and changes of water flow and sediment transport,the deposition ratio formulas are derived. Erosion-deposition characteristics during the different period are analyzed based on water and sediment continuous principle and sediment transport characteristics in the Chongqing Reach. The river deposition ratio has an important relationship between the convergent flow ratio of the Jialingjiang River and the discharge at the Cuntan Station. Scour and deposition characteristics of the Chongqing Reach during the initial stage of the TGR operation is similar to that before the TGR operation with the deposition during the flood period and erosion during the dry season. Scour and deposition characteristics in the Chongqing Reach have changed since the TGR experimental operation period in 2003-2008. In the storage period after flood period and the fall period before flood period,accumulate deposition will occur in spite of alternate erosion-deposition in the reach. In the flood period,the scour and deposition will also occur with a total small deposition,even erosion. At the same time,river sand excavation optionally has a serious impact on scour and deposition in the Chongqing City Reach.