Urban Flood Maping for Jiaxing City Based on Hydrodynamic Modeling and GIS Analysis

ABSTRACT Zhong, G.H.; Liu, S.G.; Han, C., and Huang, W., 2014. Urban flood mapping for Jiaxing City based on hydrodynamic modeling and GIS analysis. Under the climate change, extreme precipitation has been increasing dramatically, accompanied by more severe floods. The low-lying coastal areas, in particular, those due to the frequent storm surges, are suffering from heavier floods. Recently, in addition to the traditional engineering measures, researchers are exploring non-engineering measures to mitigate damages caused by flood. Development of flood risk maps which assess the vulnerable zones in the floodable (i.e. flood prone) areas is one of these non-engineering measures. Jiaxing City, a key central city in the Yangtze River Delta Area, China, is the study area in this research. Considering its particular features such as low-lying topography, dense rivers, numerous dyked areas, river flow affected by the tides and intensive human activities, a coupling hydrodynamic model of one-dimensional and two-dimensional from MIKEFLOOD is applied to identify areas prone to flooding events for specific return periods. On the basis of the flood risk analysis, spatial analysis and display functions of Arc GIS, the Flood Risk Map is compiled automatically and flood management system is developed for Jiaxing region. As a flood precautionary measure, it not only alerts the public on flood risk issues and reduces flood risk more efficiently in the identified vulnerable areas, but, also helps relevant authorities to make decisions on spatial planning and development strategies, as well as flood control and disaster relief.