The invention discloses an automatic
river network grading and river topological relation identification method based on a
graph theory, and relates to the technical field of hydrological geographic information. The method comprises the following steps: acquiring and cleaning a vector
river network, a key
point location and DEM data of a target
drainage basin; constructing an initial
river network graph model based on the
line element connection relationship; integrating DEM topographic evidence and
graph theory connection features, constructing and solving a global
potential energy field equation containing topographic driving and boundary constraint, and calculating flow
potential energy attributes of nodes of the whole network to determine a flow relationship; based on the flow direction relation, identifying topology abnormal structures such as strong
connectivity components in the network, and performing ring breaking
processing by using direction confidence to generate a ring-free directed
network structure; and performing river grade division based on a topology
transfer rule, and associating the key
point location to a river network skeleton. According to the method, through global
potential energy field solving and
topological optimization, the problems that the flow direction of the plain micro-geomorphic area is difficult to recognize and complex loops cannot be graded are solved, and automatic construction of the river
network topology is achieved.