长江中游下荆江蜿蜒型河道成因初步研究

Preliminary Study on Forming Condition of Lower Jingjiang Meandering Channels of Middle Yangtze River

描述了下荆江蜿蜒型河道河型特点。在前人所作下荆江成因研究的基础上,分析指出了下荆江蜿蜒型河道形成条件,即通过加大河长耗散富余能量并与相对较大的含沙量相适应形成蜿蜒河型,表现为河道纵向输沙平衡条件和适度抗冲的二元相结构边界条件。并将其与长江中下游分汊型河道成因进行对比分析,提出了二者在河型调整中的共性和特性。

Firstly, the patterns and characteristics of Then, based on achievements of previous researchers, the Lower Jingjiang meandering channels are described. the forming condition of the Lower Jingjiang meandering channels is analyzed. The meandering channels could be formed through increasing the length of river channels to dissipate redundant flowing energy and self-adaptation to relative higher sediment concentration. The forming condition actually reflects the equilibrium condition of longitudinal sediment transport and the boundary condition of moderate erosion-resistance capacity of dual-texture bank. Finally, compared the forming condition of the Middle and Lower Yangtze braided channels with that of the Lower Jingjiang meandering channels, the similarity and difference of characteristics between them in forming processes have been researched.