LID控制下城市成涝风险规律与防涝应急研究

Study on the Risk Regulation and Emergency of Urban Waterlogging in Control of LID

为研究LID控制下城市内涝应急响应规律,以SWMM模型为工具,在汉口某小区模型的基础上建立年径流总量控制率85%的城市模型,依据芝加哥降雨模型和汉口暴雨公式,设置降雨历时为2和4小时,重现期为1、2、5、10年的降雨强度序列开展成涝风险性研究。结果表明:重现期的变化不影响内涝显现时刻及内涝风险程度二者的变化规律,即重现期相同时,短历时降雨内涝显现时刻提前于,内涝风险程度高于长历时,且随着重现期的增加,长、短历时降雨作用下内涝显现时刻均略微提前,而内涝程度均逐渐加深;存在临界重现期使得在此重现期范围内,短历时降雨作用下内涝时长较长历时更长,而超过该重现期,表现出与前述相反的规律。基于此,提出采用基于贝叶斯决策理论和二区间数方案优选理论应急决策方法,并以重现期为10年、历时2小时的降雨强度序列为决策情景进行防涝应急决策,决策选择方案a6为应急救援方案,表明了该决策方法在LID控制下城市内涝应急决策上的适用性。

To study the law of emergency response of urban waterlogging in control of LID,based on the model of SWMM,an urban model with 85% control rate of annual runoff is established based on one district model in Wuhan.Setting rainfall intensity sequences of 2,4 hours duration and 1,2,5 and 10 years recurrence period based on the Chicago rainfall model and rainstorm formula of Hankou to do the risk of waterlogging study.The results showed that：1）The change of the recurrence period does not affect the change of the internal time and the risk degree of waterlogging.When the recurrence period is the same,waterlogging appeared time of short duration rainfall is earlier,risk level is higher than long duration.Moreover,with the increase of recurrence period,the time of waterlogging appears slightly ahead of the long and short duration rainfall,and the degree of waterlogging is gradually deepened.2）There is a critical recurrence period,which makes waterlogging duration of short duration rainfall longer than the long duration rainfall while the recurrence period in range of it,and show the opposite law beyond it.Based on these,put forward the emergency decision method which based on the bayesian decision theory and the second interval number scheme optimization theory and take the rainfall intensity sequence of 10 years and 2 hours was used to make the decision,choosing a6 as the emergency rescue plan,showing that the applicability of the decision-making method for waterlogging emergency decision in city which in control of LID.