Small watershed boundary correction method

The invention discloses a small watershed boundary correction method, which comprises the following steps of S1, calculating the gradient and the slope direction of terrain in a region by adopting DEM data to obtain terrain data; s2, combining the topographic data in the step S1 with a remote sensing image to construct ground feature indexes, wherein the ground feature indexes comprise position information and elevation information of ground features in the region; and S3, obtaining a small watershed preliminary boundary, correcting the small watershed preliminary boundary by adopting the surface feature indexes in the step S2, and performing refined division on the small watershed preliminary boundary based on the surface feature indexes to complete correction of the small watershed boundary. The method has the advantages that on the basis of hydrology, the surface catchment relation and the natural catchment unit are fully considered, the small watershed boundary correction method based on the ground featur