The Progress in the Research of Anastomosing River

Anastomosing river, as a new fluvial river pattern, has attracted more and more attention of geomorphologists, hydraulic engineers and sedimentologists. Research on anastomosing river is in great demand of the geomorphology, hydraulic engineering and sedimentology. In this paper, after introduction of the basic concept of anastomosing river, the channel plantform and boundary condition, sedimentary characteristics, hydraulic condition of this river pattern are reviewed based on comprehensive references. Furthermore, in the same fluvial system the spatial transformation between anastomosing and another river patterns is also discussed. Some weaknesses and aspects needing more attention on study of anastomosing river are pointed out. These aspects are mainly following. (a) The dynamical mechanism of the avulsion for anastomosing river formation has not studied clearly till now. It needs theoretical explanation and simulation in laboratory or digital model. Obviously, there have some difficulties. (b) The hydraulic dynamics of anastomosing rivers are still unclear because few study has been actualized on fluvial dynamics for multiple channel rivers, especially for anastomosing rivers. Besides, the hydraulic characteristics have some differences between multiple channels. The explanation to every channel of an anastomosing river system is not the same always. The stream power (including gross stream power and specific stream power) is also different between different channels of an anastomosing river system. (c) The scatter values of channel slope and bankfull discharge for anastomosing rivers have not a clear law. One of the causes is that the river number studied fully by researchers is few and distributed in different climate zones. This demands researchers to study much more anastomosing rivers.