At present,the ‘Golden Waterway’ of the Yangtze River confronts with new changes of flow and sediment conditions induced by integrated operation of the Three Gorges dam and its upstream reservoir groups.Meanwhile,there are new demands from flood risk management,navigation,electricity generation,water supply and ecology,etc.It is urgent to reveal mechanism of bed morphology evolution and predict its tendency,to develop methods for evaluating waterway capacity and potential,to develop novel waterway technologies satisfying demands of the integrated high efficiency utilization of water resources,and to merge waterway regulation and ecology protection.In the view of actual waterway situation,the project,aiming to enhance the transportation capacity of the Yangtze River and improve the water resources utilization efficiency,has condensed four key scientific issues:1) mechanism of waterway evolution and its tendencyunder variation condition of water and sediment;2) biology and habitat response to waterway regulation;3) theory and technology for shoals groups regulation of the Yangtze River under multi-factors;4) merge and rehabitated technology of waterway regulation based on river completeness.Moreover,combining the connotation of the key scientific issues,five key research contents have been proposed:1) investigate complex dynamic process and interaction between channel and bar for different types reaches,and predict waterway evolution trend;2) build framework and evaluation system for ecologic waterway of the Yangtze River;3) evaluate waterway transportation capacity and its potential for the multi-function river;4) study on technologies for gravel bar groups interlocking in the mountain river under operation of multi-reservoirs,strong erosion in the middle Yangtze River with demands of both flood defense and navigation,channel and bar regulation featuring with multi-channel branches in the lower Yangtze River,coordination regulation and deposition mitigation in the reaches under influence of river and tidal;5) develop merging and rehabitation technology of waterway in the Yangtze River,build framework for ecology-friendly waterway regulation.Finally,eight frontiers have been specified from the five key research contents:1) river evolution mechanism and trend prediction under new water and sediment condition;2) framework and evaluation system for ecological waterway in the Yangtze River;3) transportation capacity and potential of the golden Yangtze River with multi-targets;4) regulation technology of gravel bar groups interlocking under operation of multi-reservoirs;5) regulation technology for strong erosion reaches with demands of both flood defense and navigation;6) regulation technology for channel and bar regulation featuring with multi-channel branches;7) regulation technology for coordination regulation and deposition mitigation under influence of river and tidal;8) regulation technology for typical ecological protection reach in the Yangtze River.Thus,the research system of waterway regulation of the Yangtze River is initially constructed,aiming to provide a theoretical and technical foundation for enhancing the navigation capacity of the ‘Golden Waterway’ of the Yangtze River.
