Causes analysis of right branch shrinkage of Fenghuangzhou in Guichi Section of lower reaches of Yangtze River
The Guichi Section is located in the lower reaches of the main stream of Yangtze River.In recent years,the right branch of the Fenghuangzhou has been continuously shrinking,which has had a significantly adverse impact on the stability of the river regime and the economic and social development along the river.However,the reason for the shrink-age of the right branch is still unclear at present.Figuring out the reason for the shrinkage of the right branch is of great significance for the subsequent governance.Based on the measured topographic data and flow and sediment data of the Guichi Section from 1970 to 2021,an analysis was conducted on the evolution and the reasons for the shrinkage of the right branch of the Fenghuangzhou in the Guichi Section.The results showed that the right branch began to shrink in the 1970s and had gone through the rapid shrinkage stage(from 1974 to 2003)and the slow shrinkage stage(from 2003 to 2021)two stages.At present,the diversion ratio in the dry season was only 2.0％.The main reason for the rapid shrink-age of the right branch was related to the mainstream turning around due to the changes in the upstream river regime and the inlet of the branch being far away from the mainstream area.The main reason for the slow shrinkage was related to the differences in the hydrodynamic conditions of the two branches at present,and the scouring dynamics of the left branch was much greater than that of the right branch.
river evolutiondiversion ratio of branchhydrodynamic conditionGuichi Section
万方数据
维普
