The invention provides a basin
sediment budget calculation method, which comprises the following steps of: arranging various types of collected basic data of a target basin into a grid form, carrying out uniform space registration, and dividing the various types of basic data based on a small basin boundary serving as a space unit of
sediment budget calculation; for each small
watershed, respectively calculating gravitational
erosion,
debris flow erosion, channel
erosion and slope erosion to obtain spatial and temporal distribution of various erosion amounts and the total erosion amount in the target
watershed; respectively calculating the
sediment yield and the
deposition rate of the small
watershed scale aiming at the four types of erosion; on the basis of the calculated sediment production, the
sediment transport amount of the small watershed
suspended load in the
main river water
system is calculated section by section according to the upstream and downstream relation of the convergence river position of each small watershed in the target watershed, and distribution of the
sediment transport amount of the
suspended load in the flowing direction of the
main river water
system is obtained in combination with sand digging, reservoir
sedimentation and the input amount and the output amount of the
suspended load in the river reach. According to the method, the sediment space-
time distribution in the basin erosion and basin sand-producing
river sediment transportation multi-physical process can be comprehensively quantified.