Forecast Simulation Study On Rainstorm Waterlogging Hazards In The Urban Area Of Nanjing City

In recent years, with the trend of global climate change, all kinds of extreme weather events occur frequently, so more and more scientific researchers pay attention to the climate change and related meteorological disasters issues.Domestic and foreign scientists began to explore related Information about natural disasters and climate change and do a lot of research work concerned with it. The majority of studies and data have shown that heavy rains and floods has become one of the most common and the most threatening meteorological disasters.And it will threaten the human survival.We have to faced the persistent and severe challenges if human development can be sustainable.Creating a fast and effective emergency warning system is necessary that we can handle the accident methodically when the disaster occur.So establish flood disaster process model and achieve flood disaster forecast is one of the important means to develop plans for disaster prevention and mitigation.It’s meaningful for reducing the life and property of the people.City rainstorm waterlogging process model is predicting process of urban water location, depth, etc. by analog city floods caused by short inner heavy rains.It can provide a reliable basis for decision that planning the layout of the city for the government Systematically and relevant departments and scientific guidance to deal with emergencies.The urban transport roads, buildings and related water systems is the main simulation object to the model which based on the urban geographic information.The model is to establish SCS models and2D basic equations of unsteady flow process model urban storm disaster.It reflects the urban complexity of the process of the evolution of water which Involved in meteorology, hydrology, remote sensing, geographic information, such as multi-disciplinary knowledge.It is a mathematical model of multidisciplinary.Firstly,this paper describes the urban forecast flood disaster simulation, which involved an underlying factor of geographic data and precipitation data processing methods;then according to the mechanism of the city flood disaster.Analysis of the process of the production and the convergence caused by urban waterlogging.secondly, according to the formed principle and method of calculation to improved correlation calculation process of urban runoff model and counted the impact of the building on the convergence.This method on the one hand to improve the urban convergence section simulation accuracy which affected by buildings,on the other hand presents a new means of extracting building density data;finally,based on the theories, models and methods to realization of Nanjing city flood disaster simulation by the use of GIS tools. And make the simulation analysis to the three times heavy rainfall which occurred in the main city of Nanjing.Realization the forecast simulation of waterlogging runoff, convergence process and water distribution and depth changes over time and rainfall.