我国西南部Karst地区溶洞伏流广泛存在，该地区筑坝蓄水将遇到库区溶洞伏流泥沙淤积问题，处理不当将影响防洪安全、综合效益、水库寿命等，目前国内外缺乏系统的研究和机理上的认识。本项目将从上游不同水沙和下游不同壅水条件下溶洞伏流的水流运动、泥沙输移、河床演变规律着手，采用资料分析、概化水槽试验、理论分析等研究手段，深入研究Karst地区伏流水沙输移机理。通过实测资料分析，探讨Karst地区天然伏流河段水沙输移特性；采用概化水槽试验，研究不同来流量和壅水程度条件下伏流及口门上下游明流段水流结构特征的变化规律，不同水沙和壅水组合条件下伏流及口门上下游明流段泥沙输移、河床演变规律；基于理论分析，建立描述伏流水沙输移的理论和方法，揭示溶洞伏流水动力场、动水压力场、泥沙输移、河床演变规律及相互作用机制。本项目研究成果可丰富和完善河流泥沙动力学、河床演变学等学科，同时具有重要的工程应用价值。

In the southwest of the country, sinking streams in karst regions are very common. In these areas, damming will encounter complicated pressurized flow sediment deposition problem, which will affect the safety of flood control, reservoir working life and the like. Currently, there is a lack of systematic research on the mechanism of cognition. In this study, the sediment transport mechanism specifically for karst regions would be studied through theoretical analysis, data analysis, and generalized flume experiment. Data analysis would be conducted to explore the characteristics of pressurized flow and sediment transport. In flume experiments, different changes of flow, sediment and backwater conditions would be purposely designed to study the flow structure characteristics, sediment transport and bed evolution of the sinking and entrance sections. Furthermore, based on the theoretical analysis, propose the theory and method describing sediment transport by pressurized flow, and reveal the interaction mechanism between pressurized flows, sediment transport and river evolution in sinking streams. The results of this study can enrich and improve the river sediment dynamics, riverbed evolution and other disciplines, and has important application value in engineering.