Author(s): Dawei Zhang, Jin Quan, Zhihan Ye, Guangyuan Kan
Linked Author(s): Dawei Zhang
Keywords: Flash Flood Guidance (FFG), hydrological model, Geomorphic Unit Hydrograph (GUH), un-gauged catchment, Beijing
Abstract: In this study, a novel conceptual hydrological model is presented to simulate flash flood process in un-gauged basins. The highlight of the new model is the utilization of the geomorphic unit with hydrograph method to simulate the overland flow process, which makes the model extremely valuable in un-gauged basins. The model was then tested in the Hongluogu headwater catchment in Beijing city and the results indicated that the new hydrological model performed well. Two villages of Beijing were selected as the research object for the FFG and they are Sihetang village in Sihetang catchment and Nanjiangou village in Nanjiangou catchment respectively. We carried on the FFG analysis as follows: First, we calculated the disaster-induced discharge (corresponding to FFG) of the two villages through the hydraulics method. Next, we assigned probabilistic rainfall by 1hr, 2hr and 3hr for the given return periods (2, 5, 10, 20, 50, and 100 year) by using Beijing Hydrology Handbook and then the hydrological model is used to calculate the design flash flood process of Sihetang and Nanjiangou, respectively. Then we can generate the relationship curve between rainfall and the corresponding peak discharge for every return period. Finally, the FFG value can be interpolated from rainfall-discharge relationship curve based on the disaster-induced discharge. The new computed FFG values of Sihetang and Nanjinggou were tested in the �7. 20� flash flood event occurred in Beijing on Jul 20th, 2016 and the result proved that the new FFG value is reasonable and reliable for real world applications
Year: 2017