Estuarine area, as a transition area between land and sea, is the most dynamic and complicated area, due to its unique location and diverse ecosystem, but yet it is also the most vulnerable and fragile area, as it may be plagued with flooding risk, erosion, subsidence and etc. As the diagram show below, estuary area is influenced by three systems: land. Sea and human activitities. With the rising awareness of climate change, the safety of estuarine area is becoming one of the most important concern and tough challenges for urban planners, as estuarine areas are commonly the most urbanized areas, where some metropolises are built on. How to balance the physical and socioeconomic needs of urbanized estuarine area with the risks from extreme weathers is a challenge today.