Water diversion scale estimation method based on flood process cutting

The invention discloses a water diversion scale estimation method based on flood process cutting, which comprises the following steps of: calculating to obtain a typical year flood process adjacent to a river water diversion section by adopting collected rainstorm data, drawing up different water diversion flows to cut the flood process, and obtaining a relationship between monthly runoff and water diversion rate under different water diversion flows; the method is applied to the whole long-series runoff process, then the tunnel design diversion flow is preliminarily judged according to the fitting relation between different diversion flows and the average diversion rate for many years, and the reasonable tunnel diversion scale is finally selected by combining technical and economic comparison and selection. According to the method, the influence of the instantaneous flood flow in the flood season on the flow capacity of the tunnel is fully considered, the method better conforms to the general water diversion