Analysis on evolution process of the Meizizhou reach of the Yangtze River from the revetment based on GIS

摘要

Based on the data, which are underwater relief maps of the lower reach of Yangtze River in the years of 1959,1970,1983,1992 and 2003 and three profiles investigated with utilizing Arc-GIS software, this paper studied the evolution process and differences in time and space influenced by revetment in Meizizhou reach of the Yangtze River. Comparing the proportion of the width and depth, and the swing velocities of the water-front and channel line, the results show that since the revetment was undertaken, the swinging range of left waterfront and channel line decreased distinctly and the channel plane distortion was controlled effectively. Then the riverbed was eroded continuously, on which the deepest point was moving towards right. The shoal on the head of Meizizhou becomes deeper and narrower. The channel trends to stability. The Third Nanjing Yangtze River Bridge has further effectively controlled the evolution process of the Meizizhou reach of the Yangtze River.