三峡库区支流河口水动力及水污染迁移特性

为进一步弄清长江三峡水库修建对支流的影响,基于EFDC模型建立了三峡库区长寿-涪陵江段三维水动力学模型,从支流所受顶托作用的角度,分析了桃花溪、龙溪河2支流河口的水动力特性及水体长期的输移规律,并利用拉格朗日粒子示踪技术分析了干支流不同位置污染物的输移路径.结果表明,支流在枯水期受干流顶托作用较大,在支流河口区均出现明显的环流区域;丰水期龙溪河口环流区减弱并消失,桃花溪支流河口环流区域依旧明显.长江干流对支流水体存在不同程度的输入作用.

Characteristics of Hydrodynamic and Pollutant Transport of the Branch River Estuary in the Three Gorges Reservoir Area

To further clarify the impact of construction of the Three Gorges Reservoir on its tributaries,a three-dimensional hydrodynamic model of Changshou-Fuling section of Yangtze River was developed based on EFDC.Then an analysis of the hydrodynamics and the long term mass transport behaviors under backwater effect in the Taohuaxi River and Longxi River was presented.There followed Lagrangian particle tracing method to analyze pollutant trajectories of different positions in main streams and tributaries.The results show that trunk river backwater played a significant role in branch river during low-water period.And distinct circulation was shown in branch rivers estuary.However,in high-water period,estuarine circulation area in Longxi river decreased and disappeared,while the one in Taohuaxi river was still evident.Different inputaction from main streams to tributaries was discovered.