The invention discloses a distributed model-oriented medium and small
watershed sub-
watershed division method, which comprises the following steps of S1, collecting
digital elevation model data, performing depression filling
processing, and extracting preliminary
river network information; s2, extracting an actual water
system, and calculating a
river network main
stream grid elevation difference; s3, adjusting
digital elevation model data according to the elevation difference, and optimizing a
river network extraction result; s4, basin morphological parameters are calculated, and basin classification is carried out through a manifold learning method; s5, constructing a sub-basin optimal threshold calculation model, and dynamically adjusting a sub-basin division threshold; s6, flow direction calculation, confluence analysis and sub-basin division are carried out, and sub-basin boundaries are optimized; and S7,
verification is carried out in combination with the distributed hydrological model, the influence of the division result is analyzed, and sub-basin division parameters are optimized. According to the method, multi-scale features, dynamic threshold optimization and hydrological
network topology are fused, sub-basin division precision, boundary continuity and hydrological
simulation stability are improved, and intelligent basin division is realized.