Estimation of mean areal precipitation based on dual-polarization radar using copula function and Its use for urban drainage modeling

Abstract

Urban flooding is a critical disaster resulting in the malfunction of the city and the loss of properties. Furthermore, urban flood prediction often requires a combined modeling process due to the complicated drainage system. In this study, the water levels and relevant inundation areas were estimated by the radar rainfall estimations and the SWMM model. Regarding the radar rainfall estimation, the joint relationship between reflectivity, phase (i.e, ZH, ZDR, KDP) of dual-polarization radar and ground rainfalls was explored through the copula function. The copula is a function that effectively joins marginal distribution functions to form a multivariate distribution function. Finally, the water level and inundation areas of Gangnam district were estimated using hourly mean areal precipitation (MAP) through radar rainfall estimations and the coupled 1D/2D urban hydrological model. The coupled model consists of a 1D conduit network model based SWMM (i.e., the RUNOFF and EXTRAN modules) and a 2D overland flow model, which links the surcharging flows at the manholes of the 1D sewer network model. AcknowledgementThis work was supported by Korea Environment Industry & Technology Institute (KEITI) through the Aquatic Ecosystem Conservation Research Program, funded by the Korea Ministry of Environment(MOE). (No. 2021003030001)