关键词: FloodArea, 暴雨洪涝, 风险预警, 临界雨量, 平原水网, 统计分析

Abstract: Accompanying with developing economy, wet-net plains locating at the down basin of large rivers are becoming more vulnerable to rainstorm events than before. Combining DEM, terrain data and meteorology-hydrology characteristics of Jiangsu wet-net plain, we handled the mechanism of rainstorm flood through analyzing the meteorological and hydrological data. The water level of Laosui River changed with the quantity and intensity of the rainfall. Based on the correlation of water level increment and accumulative rainfalls, we modeled the linear relations during 2007-2011 and got a series of critical rainfalls. Then the heavy precipitation event occurred in 2010 was chosen to testify the statistical rainfalls. Inputting the hourly precipitation into FloodArea (FA), the water level dynamics were grasped which correlated with the input precipitation powerfully. Compared with the statistical results, the thresholds calculated by the FA model showed smaller value at higher risk level and greater value at lower risk level, but the variability is almost less than 5%. The recurrence periods of critical rainfalls in 24 h are 167 a, 17 a and 2 a, respectively. With observation data, the relationships of precipitation-water level can be analyzed adequately, especially in short duration, while FA method has advantage in evaluating long duration correlation. The data from statistical method and FA simulation can be integrated and used as indices in flood disaster warning. Selection of proper indice is a key point of risk warning services.

Key words: critical rainfall, FloodArea, rainstorm flood, risk warning, statistical analysis, wet-net plain