The Yangtze river (China) is one of the biggest rivers in the world in terms of length, area, discharge and sediment load. The large sediment supply by the Yangtze river resulted in the development of large coastal wetlands in its estuary, which form rich and important ecosystems. Human activities are increasingly influencing the Yangtze estuary, for instance by the construction of plentiful dams in the river. The precise consequences of human interventions and the effects of climate change like global sea level rise, for the tidal flats are uncertain. In the last decades, the flats have been increasing in size, while measurements from recent years indicate a stop of this growth. Investigation of the development of the tidal flats is important for preserving nature, planning further land reclamation projects and coastal defence issues.