Mountain area fine water system extraction method based on remote sensing image

The invention relates to the technical field of river information interpretation, discloses a mountain area fine water system extraction method based on a remote sensing image, and aims to solve the problem of insufficient precision of existing mountain area fine water system extraction. Preliminarily extracting a mountain area fine water system by adopting a random forest algorithm; solving the correlation between the average gradient of the drainage basin and the catchment area based on a digital elevation model, and interpreting the catchment area at the first turning point and taking the catchment area as a critical catchment area; and correcting the preliminary extraction result by using the critical catchment area to obtain the final mountain area fine water system of the drainage basin. The method improves the extraction precision of the small water system in the mountainous area, provides a scientific basis for simulation of the river flow process of the small water system in the mountainous area, has