Possible siltation downstream the tidal barrage at the branch river of Qiantang River estuary;

With its river mouth filled up, extended, drove up, switched and changed courses in the history, it formed a complicated micro-geomorphology composed of terraces, present flood plains, embanked back swamps and isolated depressions based on abandoned river beds with new and old river courses overlapping.

3D modeling of micro-landform of terrace;