Abstract Sediment plays a very important role in the functioning of river ecosystems. It is the basic substance for the survival of benthic animals and aquatic plants. On the other hand, the growth of biofilms and bio-disturbance of benthos affect the sediment transport characteristics. With the increasing attention to protect aquatic ecosystems, the importance of habitats has become increasingly researched. The need to study the interactions among sediment, flow, riverbed deformation, and aquatic ecosystems naturally leads to the proposed discipline of eco-fluvial dynamics. In this paper, the basic concept and main research content of eco-fluvial dynamics is introduced with the Yarlung Tsangpo River as the research example. This case study is an example of an aquatic ecosystem in an ever-changing environment because of the effects of climate change. The results of analysis of eco-fluvial dynamics will provide a scientific basis for decision support for the government.