In order to study regional flood risk, to develop hazard maps, alarm systems and emergency plans for flood controls, floods due to dam break have become an important issue of study because of their properties of highly un predictability and destructivity. A parameter model, a relatively simple and physically based model and an instantaneous dam break model are proposed in this paper for the study jointly. A case study was carried out in the Quan min reservoir located in Guang an municipal of Sichuan Province. Results indicate that the accuracy and the variation range of the predications can be made more accurate and certain by applying the three models together for the study of dam break floods. Therefore, an effective flood control measure can be developed based on the results of the study. In addition, whether an emergency plan should be started or not in real time operations can be made accordingly on the basis of the results predicated.
