Extraction of River Network Information in Heihe Basin Based on HEC-GeoHMS

Based on the HEC-GeoHMS module, this paper extracts the river network information of the Heihe River Basin effectively by using the Digital Elevation Model (DEM) obtained free of charge. By the steps of filling the sinks, determining the flow direction, flowing accumulation and streaming definition, we get the river network density corresponding to the thresholds of different confluence accumulations in the basin. By fitting the curve of the relationship between the threshold of sink flow and the density of the river network, we conclude that the most suitable threshold for the accumulation of the Basin is 42.3km
²
. In addition, the river network density decreases with the increase of the confluence accumulation threshold. But when the confluence accumulation threshold increases to a certain value, the change of the river network density becomes stable. According to the value of which the density tends to be stable, the river network information in the Heihe River Basin can be extracted effectively, which provides basic data for the establishment of the hydrological model in the region.