Study on urban flood early warning system considering flood loss

As an effective way to reduce flood loss, flood early warning system (FEWS) plays an important role in the disaster reduction paradigm. With the frequent occurrence of urban floods, it is of great significance to study urban FEWS. Considering the spatial difference characteristics of flood loss, this paper proposed to build a multi-information early warning system including rainfall information, inundation information and disaster information. First of all, establishing the land use type division and flood simulation superposition model, the rainfall and inundation information of all kinds of building property types can be obtained. Then the disaster information can be obtained through the calculation of submergence depth-damage rate-loss value relationship of different building property types. Finally, dividing the loss threshold through the Iterative Self Organizing Data Analysis Technique clustering method. Through the comparative analysis of submergence depth early warning and flood loss early warning, it is found that there were differences in the direct loss of building property types under the same submergence depth, in which the residential areas were most affected by floods and the commercial areas had the greatest economic loss. At the same time, due to the high population density in residential and commercial areas, the government and relevant departments should make preparation for waterlogging emergency and rescue in those areas in advance, pay close attention to the rainfall situation and release early warning information in time. It is expected that the research results can provide scientific basis and guidance for disaster prevention and mitigation decision-making and the development of FEWS for flood affected areas in the world.