Method for determining outlet position of multi-stage river basin based on DEM

The invention belongs to the technical field of river basin information extraction, and discloses a method for determining the outlet position of a multistage river basin based on DEM, including: determining density of river network; generating streamway link points; generating a subbasin with the streamway flow node as the water outlet; counting the maximum flow accumulation of subbasins at all levels; calculating the water outlet point of subbasins at all levels; vectorizing the water outlet points of each subbasin; obtaining the position of each control node in the river basin; obtaining all nodes in the river basin; generating the final subbasin and watershed based on all nodes and flow directions in the river basin. The invention realizes the automatic acquisition of the outlet positions of multi-level river basins, and provides technical support for hydrological simulation of river basins and water resources allocation.