基于日降雨量的城市内涝灾害风险评价——以长春市南关区为例

Risk assessment of urban waterlogging disaster based on daily rainfall in Nanguan District, Changchun City

目前,对于城市内涝灾害风险评价一般是以极端降水作为指标,这样往往会导致城市内涝灾害发生的程度被低估,中等或较弱降水也可能是城市内涝灾害致灾因子之一。为精确地评估城市内涝灾害风险,以长春市南关区为例,以1985~2015年逐日降雨强度的分布分析为基础,将逐日降雨强度转换为降雨超越概率(PEP)指数,将逐日的降雨强度与年最大日降雨量超越概率进行比较,得到城市内涝灾害发生概率,并构建了城市内涝灾害风险评价指数,对2019年南关区内涝灾害风险进行评价。结果表明:2019年南关区内涝灾害风险评价指数为0.597,为重大风险中的显著风险。研究成果可为精确评估城市内涝灾害风险提供参考,为城市内涝灾害防范提供决策依据。

At present, the risk assessment of urban waterlogging disasters generally uses extreme precipitation as an indicator, which often leads to underestimation of the risk degree of urban waterlogging disasters.Moderate or weak precipitation may also be one of the disaster-causing factors of urban waterlogging disasters.In order to accurately assess the risk of urban waterlogging disasters, taking Nanguan District of Changchun City as the object, based on the analysis of daily rainfall intensity distribution from 1985 to 2015,the daily rainfall intensity was converted into a precipitation exceedence probability(PEP) index.The rainfall intensity was compared with the precipitation exceedence probability based on annual maximum daily rainfall to obtain the probability of urban waterlogging disasters, finally the urban waterlogging disaster risk assessment index was constructed to evaluate the waterlogging disaster risk in Nanguan District in 2019.The results showed that the waterlogging disaster risk assessment index in the study area was 0.597 in 2019,which was a significant risk among the major risks.The research results can provide new ideas for accurately assessing urban waterlogging disaster risks, and can also provide decision-making basis for urban waterlogging disaster prevention.