A review on morphodynamic processes and mechanism of braided rivers
摘要
Braided river as a primary alluvial river pattern is of great importance on fluvial geomorphology, aquatic habitat, river exploitation and ecological protection. According to the literature review on braided rivers, the basic definition and morphological characteristics are described, and several classic methods and parameters of morphological characterization are introduced. In addition, field methods of obtaining high-precision DEM are summarized as well as the application of flume experiment and numerical model which advantages and disadvantages are pointed out, respectively. This paper describes the general composition of different morphological units of braided river, and lists the evolution mechanism of bar formation, anabranching adjustment and lateral migration, bank erosion and floodplain deposition. The primary controlling factors of morphodynamics and evolution of braided river, such as stream power, bed sediment particle size, sediment supply, riparian vegetation and valley width, are compared and analyzed. Meanwhile, a promising direction for alluvial river dynamics is to unravel formation causes, morphological characteristics, and fluvial processes of braided rivers with different spatial scales on the Qinghai-Tibet Plateau.