LIU Jia-jia, ZHOU Zu-hao, JIA Yang-wen, WANG Hao

State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, IWHR, Beijing 100038, China

Abstract: The AGREE and burn-in algorithms are far-flung methods for the river extraction from DEM based on the modification of the actual river information, from which the extracted simulated river networks are closer to the actual ones. But in some situations, the extracted river networks may be disconnected. The reason for the drainage network disconnection is the wrong flow direction calculation from the “overestimation” and “underestimation”, and most of them could be eliminated, i.e., the drainage network disconnection could not happened. The sufficient condition of the drainage network disconnection is that there must be “overestimation” in the river grids and its influence could not be eliminated by drainage network ex traction processes. Thus, an improved method is promoted. First, the elevation of the river grids within the DEMs are modified to make sure that the upper river grids are greater than the lower river grids, i.e., eliminating the effect of the “overestimation”. Second, the Burn-in or AGREE method is used to extract the river networks. The application to the Weihe River Basin reveals that the improved method could solve the problem of river “disconnection” efficiently, and could be used for the elevation modification.

Key words: Burn-in algorithm; AGREE algorithm; river network extraction; river network modification; Improving

Published in: Journal of China Institute of Water Resources and Hydropower Research (Vol. 11 No. 3, 2013)