Surface Rainfall Calculation Of The Storm And Rainstorm Waterlogging Model Research Of Hangzhou City

In recent years, urban development speed, as the extreme rainstorm frequency increases, the city waterlogging disasters deposition seriously affects the life property safety of the urban residents. Based in hangzhou urban area as the main research object, the rainstorm waterlogging deposition model calculation method of the principle, surface precipitation problem such as comparative analysis, combining with WRF, GIS technology, in view of the heavy rain product by reducing waterlogging caused by urban disasters and to provide scientific basis.Paper discusses the main conclusions are as follows:1.1951-2011 year by year in hangzhou city daily precipitation data statistics, from the year, month precipitation extreme precipitation and precipitation days and days extreme value to the analysis of hangzhou strong precipitation characteristics of climate change. Analysis:nearly 60 years of hangzhou precipitation intensity has obvious strengthening trend of storms appear more frequently than in previous years; Affected by the monsoon, may and June for the rainy season, but in the meiyu front, under the action of continuous precipitation process is also accompanied by heavy rain the weather; 7-9 months for the typhoon season, in the tropical cyclone and, under the influence of heat convection rainstorm disaster happens.2.According to a 2012-2013 in hangzhou summer (June-September) in the center of the storm rainfall data, the analysis of the effect of topography on rainfall, using the voronoi, quadric surface method, inverse distance weighting method and kriging method for simulating the surface precipitation of the hangzhou city center distribution analysis, get the following conclusion:the four kinds of surface rainfall calculation methods have their own advantages, quadric surface method can effectively reflect the spatial distribution of the rainfall of rain storms in hangzhou city by topographic factors, the surface precipitation of the simulation results are more accurate; According to four kinds of value as a percentage of the relative error of interpolation results shows different precipitation time scale differences between the results of the simulation precision, overall, the precipitation time scale, the greater the effect simulation is more accurate.3.Using SCS model, combined the technology of ArcGIS modeling, simulation respectively on August 10,2012, on August 1,2013,2013 on August 19, such as rainstorm precipitation process for many times, according to the historical flood point data analysis of the test, the following conclusions:SCS model principle is the key to the selection of CN value, according to "national engineering handbook", CN value of reference to choose suitable for hangzhou city. Modeling the main process for the grid information reading, processing and analysis. By calculating rainfall data from each grid surface rainfall and land use type and soil into the SCS model; Drainage pipe network, DEM data and density data on pipe network draining and ground bus way to the bus model, model calculation results. Simulated precipitation process for many times, on August 19,2013, a heavy rain process simulation in this paper. Through to the hangzhou main city flood and rainstorm waterlogging deposition of hangzhou urban area comparative analysis of simulation results, basic can confirm model simulation results and the actual historical waterlogged.