River erosion-lessening and siltation-promoting device and its allocation method

A river erosion-lessening and siltation-promoting device is installed in a river. The river erosion-lessening and siltation-prompting device comprises a plurality of structure strips and a plurality of stream-disturbing bands. The structure strips are interconnected to form a plurality of passage spaces through which water may flow and the stream-disturbing bands are connected to the structure strips to disturb water streams so as to achieve an effect of reducing flow speed and promote siltation. The installation method of the river erosion-lessening and siltation-promoting devices is to arrange a stepped bed fixation construction of which the elevation is stepped down in the downstream direction. A cutoff wall that extends to the bed is mounted downstream the bed fixation construction. A plurality of erosion-lessening and siltation-promoting devices can then be installed downstream the bed fixation construction and the erosion-lessening and siltation-prompting devices are interconnected as a geometric array