Preliminary building and application of Beijing urban flood models
XU Mei1,2, SUN Yang3, LIU Shu1,2
1. China Institute of Water Resources and Hydropower Research, Beijing 100038; 2. Research Center on Flood and Drought Disaster Reduction of the Ministry of Water Resources, Beijing 100038; 3. Beijing Water Authority, Beijing 100038
Abstract:Flood prevention task of Beijing downtown is becoming more and more urgent in recent years under the current situation of frequent floods and waterlog caused by extreme weather and rapid urbanization. Advanced wa-terlog warning based on rainstorm forecast will be one of the affective methods for flood prevention. In this context, Beijing urban flood models has been built gradually in recent several years, including a set of generalized models covering Beijing downtown area about 1 426 km2 and a set of refined models covering Qinghe Basin and Liangshui-he Basin of Beijing downtown. Each set of the model includes 1-D river model, 2-D surface model, underground pipe model and coupling model. The generalized models run fast, but the result is in low accurate. The refined models require long computing time, but the results are in high accurate. Two sets of flood models of different ar-eas can be combined together according to the practical requirements. During flood seasons, hourly rolling simula-tion are carried out according to rainfall forecast, which supports urban river sluice and dam dispatching and the release of waterlogging risk. In order to meet the requirements of rapid analysis and evaluation, more than 500 sce-narios of different magnitudes and durations of design rainstorms and typical rainfall processes in Beijing are simu-lated and analyzed in advance, and a rainfall-waterlogging scenario database is built, which played a more exten-sive role in flood discharge analysis of river channels, drainage analysis of pipe networks and standing book con-struction of ponding in bridge areas.