河流水沙供给为河口三角洲的发育提供了必要的物质来源和动力条件，因此河流的入海流路和三角洲的海岸线都对流域来水来沙条件的变化极为敏感。黄河河口三角洲是世界河口海岸带中的典型区域，近几十年来水来沙过程发生了显著变异，河口三角洲的生态系统和社会经济可持续发展正经历着严峻考验，迫切需要对三角洲的动力地貌变化特性及发展趋势进行科学研究。本项目将利用遥感和地理信息技术，结合野外实际观测、室内分析等手段，详细分析黄河三角洲清水沟流路和海岸线的时空演变特性、来水来沙年际和年内的变化过程、入海流路和海岸线对来水来沙变化的响应机理。在此基础上，确定河口冲淤动态平衡的临界水沙条件，并根据河流、潮流和洋流相互作用的时空分布特征，探讨三角洲地貌发育的物理模式及关键过程。这一研究将有助于深化对河口地貌演变规律的科学认识，并为黄河三角洲的生态保护、资源开发与利用以及黄河流域水资源合理配置提供科技支撑。

Water and sediment supplied by rivers provide material sources and dynamic condition for delta development, such that the shorelines and river mouth channels of deltas are extremely sensitive to the variations in water and sediment supply. The Yellow River delta is a typical region in the global coastal zone and has experienced a sharp decline in water and sediment supply in recent decades. This has imposed considerable threads to the regional ecosystems and social economic sustainable development and it is urgent to know how the delta changes its morphology and the tendency of future evolution. By combining remote sensing satellite images with field observations, this project examines the characteristics of the spatial-temporal changes in the channel and shoreline of Qingshui river mouth, the variations of water and sediment supply at inter-annual and in-year scales, and the responses of the river mouth morphology to the variations of water and sediment supply. Consequently, this project will determine a reasonable critical condition of water and sediment inputs for land accretion in the delta and explore the responding mechanism and mode of delta morphologic development in terms of the spatial-temporal interactions among the river, tides and the ocean. This study will deepen our understanding of the principles governing the morphologic evolution of deltas and meanwhile provide scientific support for decision making on the ecological protection and resource exploitation of the Yellow River delta and the water resources allocation in the entire drainage basin of the river.