中文摘要：

库区交汇河段受坝前水位升降与干支流流量丰枯的影响,其侵蚀基面具有双重变化特性,从而产生特殊淤积形态。基于大量实测资料,对库区交汇河段干流与支流河道纵向淤积形态进行分类,提出支流纵剖面倒坡锥体淤积与锥体—倒坡锥体过渡淤积两种特殊类型。从水库运行方式与干、支流顶托两个关键因素入手,将水动力条件的变化与干、支流淤积形态建立联系,指出双重顶托的存在为库区交汇河段淤积形态差异的内在机理。

英文摘要：

As the confluence reach in reservoir area is impacted by the change of the water level before dam and the flow variations of both the mainstream and the tributaries,its erosion basis has a dual variation characteristics,thus unusual deposition patterns are to be formed therein. Based on a large amount of observed data,the longitudinal deposition patterns of both the mainstream and the tributaries of the confluence reach in reservoir are classified,and then two unusual deposition patterns of the longitudinal section,i. e. deposition of inverted cone and the transition deposition of cone-inverted cone are put forward. From the aspect of two key factors those are the operation mode of reservoir and the backwater effects from the mainstream and the tributaries,a relationship is established between the change of the hydrodynamic condition and the deposition patterns of both the mainstream and the tributaries,and then it is pointed out that the dual backwater effect is just the inherent mechanism of the difference among the depositions formed in the confluence reach in reservoir area.