The evolution analysis of Fengcheng reach under the changing conditions

摘要

Impoundment of upstream reservoir, construction of Ganjiang highway bridge and actualization of navigation regulation project changed the incoming water & sediment condition and boundary condition of Fengcheng reach and consequently brought to the reformation process which caused adjustment of local river regime. Based on flied data and model experiment, river evolution and reformation process tendency in Fengcheng reach under changing conditions was analyzed. Furthermore interaction between reformation process and changing conditions was interpreted as well as the influence to navigation and near-shore project. It is concluded that after change of the condition general scour occurs. Left branch downstream highway bridge has gradually declined while mid branch has developed to be the main channel. Evolution tendency presents as shoal line recession in Sha-shoal and thalweg swing rightwards in mid bending part and thalweg deepen and widen in mid branch. The reformation will influence navigation condition and near-shore project in a long run.