Numerical Simulation Of Urban Waterlogging And Its System Design Based On GIS

Urban waterlogging refers to the urban area within, due to the short-time rainfall intensity is large, while urban surface impervious area of infiltration capacity, moisture-holding capacity is weak, so in short intense rainfall when surface runoff formation under a regional flood disaster. Numerical simulation of urban waterlogging is intended primarily for waterlogging occurs before, during, and after the three main processes of numerical analysis and simulation, On the building of the city is a non-disaster management of engineering project, and provide the decision-making basis for urban flood control and drainage, is of great practical significance. This paper combined with knowledge of meteorology, hydrology, geography and Geoscience expression according to the causes of waterlogging, hydrological processes, waterlogging of theoretical analysis of process and results, such as, the establishment of a numerical simulation system of urban waterlogging. First set out the geographical data processing method of urban waterlogging of underlying factors, according to city DEM extraction of urban land surface hydrology and related factors, and analysis. Secondly, Analysis of the convergence of urban waterlogging of precipitation, runoff, and other processes, and in accordance with its principles and calculation methods, application of secondary development of GIS for modeling. Then, with urban municipal pipe network information to establish the urban drainage modeling, network capacity and urban DEM amendment, making urban drainage of model parameters, calculation and simulation of spatial-temporal distribution of urban waterlogging. Finally this article in Jiading district of Shanghai as a study area, simulating a one-hour heavy rainfall waterlogging of the distribution and design of GIS system for generation of thematic maps, analysis of causes of waterlogging and the source of error. Research results show that the numerical calculation results more accurate, analogue of waterlogging and water depth than match the reality, and there is a certain degree of error, depends on the accuracy of the data and integrity constraints.