东津河流域暴雨洪涝灾害风险区划

本文从暴雨致灾机理出发,以东津河流域为例,开展中小河流域暴雨洪涝灾害风险区划技术研究。根据气象资料、水文资料、地理信息资料、社会经济统计资料以及历史灾情资料等,运用TOPMODEL水文模型并结合统计法确定致洪临界面雨量,利用逐步回归法重建区域站资料序列,基于广义极值分布函数计算出不同重现期的致洪面雨量,根据流域内小时降水雨型分布,将不同重现期致洪面雨量以及叠加堤坝信息的DEM、manning系数等数据代人Flood Area模型进行洪水淹没模拟,得到不同重现期下洪水淹没图,再叠加流域内栅格化的人口、GDP以及土地利用信息,最终得到不同重现期下人口、GDP以及土地利用等风险区划图谱。建立的中小河流域暴雨洪涝灾害风险区划技术方法简便可行,区划结果精度高、实用性强,对于面向实时防灾减灾的动态灾害风险管理具有重要意义。

Rainstorm Flood Risk Regionalization of the Dongjin River Basin

Beginning with the mechanism of rainstorm floods, and taking the Dongjin River Basin as a case, this paper carries out the study on the rainstorm flood risk regionalization of medium and small river basins. Using the meteorological data, hydrological data, geographic information data, social and economic statistical data, historic disaster data as well as the hydrological model of TOPMODEL and statistical method, we determine the flood critical area rainfall and also reconstruct the data sequence of regional meteorological stations by the method of stepwise regression. Then by using the generalized extreme value distribution function, we work out the flood causing area rainfall in different return periods. According to the distribution of hourly precipitation rainfall pattern in the river basin, we use the FloodArea model to simulate the flood with the data of the flood causing area rainfall in different return periods, the DEM added with the dyke dam information, and the coefficient of manning etc., obtaining the flood inundation maps for different return periods. Finally the risk regionalization atlas for different return periods are drawn based on the data of population, GDP and landuse in the river basin. The technique established in this paper for rainstorm flood risk regionalization of medium and small river basins is convenient and feasible, and the results of risk regionalization are of high precision and strong practicability. Therefore, it is meaningful for dynamic disaster risk management which faces the real time disaster prevention and mitigation.