关键词: 河道地形; 外包边界; 格网划分; 河道DEM; 水文泥沙; 长江河道;

Abstract: The outer boundary of river channel terrain is a key constraint parameter for generating river terrain DEM data, which is very important to the analysis and calculation of hydrological and sediment by topography method.In order to improve the delineation efficiency of river complex terrain boundary, this paper proposes an automatic generation method of outer boundary based on plane discrete points.This method extracts the measured point data of the river terrain, quickly determinates the boundary grid closed-loop by grid division.After searching and scanning the discrete points in the adjacent boundary grid, the outer boundary of river channel terrain is generated.By this way, the automatic search of the terrain outer boundary of Yangtze River channels at different scales is realized in GeoHydrology system software.Based on this, the system completed the generation of terrain DEM,the calculation of fluvial bed storage volume, and drawing of erosion and deposition thickness map.The results show that this method can quickly provide more accurate boundary constraints for the complex river channel terrain of the Yangtze River, and has the advantages of strong adaptability, fast generation speed and fitting the actual shape of river channel, which improves the timeliness and accuracy of management and analysis of hydrologic and sediment information in the Yangtze River.

Key words: river channel terrain; outer boundary; grid division; river channel DEM; hydrologic and sediment; Yangtze River channel;