The application discloses a
river network grading and river topological relation automatic identification method based on
graph theory, and relates to the technical field of hydrological geographic information. The method comprises the following steps: acquiring vector
river network, key points and DEM data of a target basin and cleaning; constructing an initial
river network graph model based on
line element connection relation; fusing DEM
terrain evidence and
graph theory connection characteristics, constructing and solving a global
potential field equation containing
terrain driving and boundary constraint, calculating the flow direction potential attribute of all network nodes to determine the flow direction relation; identifying topological abnormal structures such as strong connected components in the network based on the flow direction relation, performing breaking treatment by using direction confidence, and generating a loop-free directed
network structure; performing river grade division based on topological transfer rules, and associating the key points to the river network skeleton. The application solves the problems of difficult flow direction identification in plain micro-
landform areas and the problem that complex loops cannot be graded by solving and optimizing the global
potential field, and realizes automatic construction of the river
network topology.