Author(s): E. Er Dun; Shanghong Zhang; Bohua Zhao
Linked Author(s):
Keywords: Urban storm-flooding model；ArcGIS；Urban area；Harbin；Simulation and calculation
Abstract: As the increasing urbanization process, the underlying surface and climate conditions have been changed due to human activities, which result in more and more frequent flooding and inundation problems in urban areas. This would in turn lead to economic loss and destruction to people’s lives and properties. Many storm-inundation models were based on hydrology and hydraulic mechanism and owing to complexities of urban areas such as terrain, soil surface and elevation conditions, etc, these models called for masses of statistics (topography, sewer conveyance and so on). Additionally, the corresponding simulation progress was rather complicated and would take very long time. The main purpose of this study was firstly establishing a flat-flow model to find inundation spots promptly, and then simulate the inundation depth and area of certain positions, finally demonstrate model effectiveness and precision through comparing with the actual measured data. The basic calculating and comparing principle was that, in case the surface runoff volume was underneath the maximum water storage of the low-depression, the calculated volume area and depth were the final achievements. Otherwise, this low-depression had been filled completely and the rainfall volume excess would transfer to the direction of the outfall of entire basin, and the flooding area and depth of this low-depression were calculated via considering its topography and actual shape. ArcGIS was utilized as the basic platform of model development and an urban area of Nangang District in Harbin was selected as the study area. Fundamental data included the primary precipitation stations, the statistics of original topography, daily rainfall depth and the actual measured area and depth, which were integrated and filtered to choose 8 flooding spots for model calibration, and 4 inundation spots for model validation. Calibrate the discounting parameter which used to calculate the volume of surface runoff deriving from precipitation in the former 8 inundation points. Then validate the inundation volume, area and depth in the latter 4 flooding points. Through the picture of curving fitting, the trend of simulation progress would be seen intuitively. After comparing the simulated results with the measured ones, the accuracy, application as well as effectiveness of model had been confirmed, which would in turn be beneficial to flood controlling and inundation forecasting in urban areas of Harbin.
Year: 2013