Loss function construction method and system based on session flood disaster

The invention discloses a loss function construction method and system based on session flood disasters. The method comprises the steps that basic data of a research area is acquired and preprocessed; constructing a simulation model and calibrating model parameters; screening flood disaster loss evaluation indexes, and constructing an evaluation index system; carrying out spatial distribution on the social economic data; performing flood simulation to obtain rasterized ponding depth data of each time step length; constructing and adopting a loss rate calculation module, calculating flood disaster loss at each moment based on the distributed social economic data, fitting a change curve of a flood disaster loss-time function, comparing fitting effects of different functions, and selecting an optimal fitting function and parameters thereof; and analyzing the relationship between the related parameters in the loss function and the disaster occurrence probability to obtain a relationship formula of the loss functi