EVALUATION OF SIMULATION EFFECT OF URBAN RAINSTORM WATERLOGGING MODEL IN GUANGZHOU

LI Haiyan; WU Xiaoxuan; WANG Ting; PAN Weijuan; XIAO Ting; YE Xiying

doi:10.16032/j.issn.1004-4965.2023.060

Abstract：In the present study,a Guangzhou urban rainstorm waterlogging model which is developed using the hydrodynamic method,combined with refined precipitation forecast data,is used to simulate the ponding depth and risk level of waterlogging points in Guangzhou.The results demonstrate that the model has a hit rate of 65%for the waterlogging risk level of the waterlogging points in the past two years,while the highest hit rate is 72.8%for the precipitation processes with accumulated precipitation of 50～100 mm.The simulated ponding depth for the precipitation event on May 22 is relatively shallower compared with the real situation,and the error is mainly found in the simulation for the ponding depth within 30 cm,accounting for about 64%.Most of the simulated ponding depth is shallower and these ponding points are mainly located in the north-central part of Guangzhou.The model has good simulation ability for ponding with depth below 1 m,while the simulation ability for deep ponding around 2 m is still limited.Moreover,the waterlogging conditions are different in the central urban area under different return periods.Under the 1-hour rain condition,the ponding depth is generally less than 20 cm,and some range within 20～59 cm;under the 3-hour rain condition,the ponding depth is generally between 20～59 cm,with some ranging between 0～20 cm and 60～119 cm.Overall,the simulation results roughly match the actual waterlogging situation,and the model accuracy can meet general operational needs.