基于GIS的南京主城区暴雨内涝灾害脆弱性研究

Study of the Vulnerability of Nanjing City Rainstorm Waterlogging Disaster Based on GIS

根据南京市暴雨强度公式,计算得出2、5、10、20、50年一遇的降水分别在20 min、40 min、1 h、2 h、3 h的降水量;然后根据土地利用数据、DEM数据、建筑密度等,将降水量代入修正的SCS水文模型,计算得出在不同重现期内不同历时的淹没水深;最后由淹没水深跟灾损率的关系得出南京市暴雨脆弱性分布,并对计算结果进行分析。结果表明,南京市鼓楼区及其周围地区的淹没水深较大,脆弱性与淹没水深相关性较大,但是脆弱性不完全由淹没水深决定,会出现淹没水深高脆弱性低和淹没水深低脆弱性高的现象。

According to the formula of the rainstorm intensity in Nanjing city,we first get the heaviest precipitation in 20 min, 40 min,1 h,2 h and 3 h in 2,5,10,20 and 50 years. With the land usage date,DEM data and building density,we put precipitation into the revised SCS hydrology model to calculate the inundation depth within different repeated periods that have different duration. In the end,we get the rainstorm vulnerability distribution of Nanjing city according to the relationship between inundation depth and disaster loss rate and further analyse the calculated results. The results of the study are shown below. There is a greater inundation depth in Gulou district of Nanjiug and its adjacent areas. A great correlation occurs between vulnerability and inundation depth but the vulnerability are not completely decided by the inundation depth. There is a chance that high inundation depth and low vulnerability or low inundation depth and high vulnerability occur at the same time.