To evaluate rainstorm and flood disaster objectively and quantitatively, in this study we discuss the operational procedure for rainstorm and flood disaster loss evaluation based on rainstorm and flood inundation model. The core components include estimating the inundated area caused by rainstorm and establishing a suitable economic loss evaluation model. Of them, the rainstorm and flood inundation model is used to calculate the rainstorm and flood confluent process based on Deterministic Eight-node and Manning formula, and obtain the inundated
area and depth of research area by giving confluent time. The economic loss evaluation model is comprised of direct and indirect economic
losses, and the direct economic loss is calculated by the cost of various types of property within the inundated area by the corresponding loss rate. Using the case of a rainstorm and flood disaster event of Wuhan Jiangxia in July 2010 as an example, in the paper we demonstrated the whole evaluation procedure. The results show that the operational procedure of the rainstorm and flood disaster loss evaluation based on the
rainstorm and flood inundation model has a clear physical basis, which represents the whole process of rainstorm—runoff—flood disaster. Being applied to day-to-day operation of disaster impact evaluation, it can improve the degree of its quantification, and offer a reference for rainstorm and flood risk management.