Real-time flood risk analysis system for Qiaosang Polder Flood Protection Zone, Guangdong Province
On Aug. 25, 2015, the project of Flood Risk Mapping for Qiaosang Polder Flood Protection Zone, Guangdong Province, one of the projects of flood risk mapping for the national key areas undertaken by NHRI Dept. of Hydrology and Water Resources, passed the technical review organized by Flood Control and Drought Relief Headquarters Office of Guangdong Province in Qingyuan. The Review Group consisted of experts from Office of State Flood Control and Drought Relief Headquarters, China Institute of Water Resources and Hydropower Research, Pearl River Water Resources Commission, Guangdong Provincial Bureau of Hydrology, Guangdong Provincial Flood Control and Rescue Technology Support Center and South China Agricultural University, listened carefully to the report of research findings. It was unanimously agreed that the project passed the technical review with advanced research technology, abundant research findings and expected targets achieved.
Qiaosang Polder is one of the 10 big polders in Guangdong Province, located at the downstream of the Pearl River Delta, a low-lying fluvial plain with complex river network, prone to the influence of upstream fluvial floods, downstream high astronomical tides, and huge local rainstorm induced inundation risk. Local rainstorm flood occurred in June 1998 made the breaches of the Nanhai Water Gate of Qiaosang Polder and the dyke of Douzha in Hecun Village, resulting in the cultivated land of over 8000 ha inundated and 119.4 thousand people affected. In accordance with the national relevant guides, regulations and requirements of Guangdong Provincial implementation plan, the project team constructed the 1D and 2D hydrodynamic models, estimated the flood risk in terms of flood, storm tide, local rainstorm, breaching and their integrated scenarios, corresponding flood damages and safe evacuation, and prepared a full set of flood risk maps, based on field investigation, detailed data collection and sorting and with the help of such technology as hydrological analysis, hydrodynamic simulation and GIS spatial analysis. The real-time flood risk analysis system and flood risk map management system for Qiaosang Polder Flood Protection Zone has been developed with the multi-functions of management of flood scenarios, real-time flood simulation, damages assessment, flood risk mapping, real-time dyke breaching simulation, and demonstration and scheme comparison of flood risk maps, etc.