Study On The Application Of Common Hydraulic Models In Waterlogging Drainage Project Of Zhongxiang City

With the continuous improvement of urbanization level of China, urban flood disasters occur more frequently, which seriously affectted the social order and people’s life, and exposed that the current urban drainage system cannot adapt to the rapid development of constructions as well. At present, traditional calculation methods have some unreasonable aspects in planning and designing urban drainage system, but hydraulic model simulation has very important significance in scientifically planning and designing urban drainage system, effectively reducing the loss caused by the urban floods, therefore, to research and apply hydraulic models have very important practical significance.This thesis took the urban flood in Zhongxiang city as the object, the writer respectively adoptted MIKE FLOOD, Info Works ICM and SWMM model softwares to build the urban drainage system model in Zhongxiang city, and discussed in detail model theories, modeling procedures and selection of model parameters. After modeling,the writer demonstrated the scientificity and reliability of three models in the condition of actual rainfall in Zhongxiang city, the result showed that: Current runoff coefficients of Zhongxiang city is about 0.71, and bed roughness of the moat in Zhongxiang city is about 0.025,and other model parameters are reasonable by demonstrating.The writer used three models simulate by designed rainfall of 2 years /20 years return period, and results showed that:(1) Beyond 74% status quo of the drainage pipe in Zhongxiang city fail to meet the basic requirement of the 2 years return period,and rising of the moat water level had influence on the drainage capacity of sewer;(2) In Zhongxiang city, area of the region with high risk of waterlogging is about 2.48km2 to 2.66km2, area of the region with moderate risk of waterlogging is about 4.12km2 to 4.65km2, area of the region with low risk of waterlogging is about 46.16km2 to 46.51km2, and low designed standard of drainage pipe network in Zhongxiang old city resulted in serious waterlogging, and low ground and incomplete drainage facilities in parts of east region in Zhongxiang city resulted in serious waterlogging.The writer used the evaluation system of analytic hierarchy process to compare three models from the aspects of applicability, accuracy and convenience, and the result showed that the comprehensive scores of MIKE FLOOD, Info Works ICM, SWMM are 89.3, 92.4, 72.0.According to the result of comparing three models, the writer adoptted Info Works ICM model software to assess urban waterlogging risk based on the recent planning, the result showed that in Zhongxiang old city area, the recent planning worked good to solve waterlogging in 11 waterlogging sites besides the area of Lu Gouxi lane; through analyzing, the writer added a rainwater storage tank of 1600 cube meters in the area of Lu Gouxi lane as the solution to solve waterlogging in this place,and used Info Works ICM model software to assess urban waterlogging risk again, the result showed that improvemet scheme with rainwater storage tank worked well to solve waterlogging in all waterlogging sites in Zhongxiang old city area.