摘要
汛期极端降雨给城市地区造成了严重的内涝威胁。首先基于近30 a上海逐日降雨数据构建了日极端降雨阈值时间序列,按照汛期降雨类型区分为梅雨期、盛夏期和秋雨期3种降雨时期,该分类的差异通过了统计检验。汛期极端降雨阈值情景表明,上海市汛期极端降雨雨量为盛夏期最大,极端降雨的空间分布与城市中心、郊区的城市化水平以及汛期降雨时期密切相关。研究基于Mike21数值模型构建城市内涝模型,模拟了汛期极端降雨阈值情景。结果表明:在90分位、95分位、99分位阈值情景下,上海郊区的受淹面积占比最大;盛夏期内涝淹没区域则主要聚集于中心城区和上海东南部,最大淹没深度达1.5 m。99分位阈值情景下,承灾体高暴露度(淹没水深>0.15 m)结果显示,道路受淹比例最高,在22%以上,建筑次之,受淹比例在8%以上,耕地受淹比例相对较小,在4%以上。汛期应重点防范99分位极端降雨事件,研究结果可为防汛除涝提供决策支持。
The intensification of extreme rainfall events during flood seasons poses a significant threat of urban waterlogging in cities.This study focuses on assessing the impact of extreme rainfall on urban waterlogging,particularly during flood seasons in Shanghai,China.Utilizing nearly three decades of daily rainfall data,we established a time series of daily extreme rainfall thresholds and categorized rainfall periods into three distinct phases including Meiyu,midsummer,and autumn rain periods,and the difference in the classification passes the statistical tests.The analysis of extreme rainfall threshold scenarios revealed that peak rainfall occurs during the midsummer period,with spatial distribution patterns closely linked to urbanization levels across city centers and suburbs,as well as temporal variations during the flood season.Employing the Mike21 numerical model,we constructed an urban waterlogging model to simulate extreme rainfall scenarios during flood seasons.Results indicate that for threshold scenarios at the 90 th,95 th,and 99 th percentiles,suburban areas exhibit the highest proportion of inundation.Conversely during the midsummer period,inundation is predominantly concentrated on the central urban and southeastern regions of Shanghai,with the maximum water depth up to 1.5 m.Additionally,the results of 99 th percentile scenario of high exposure to waterlogging(with inundation depth>0.15 m)indicate that roads are the highest exposure,with inundation rates exceeding 22%.Buildings follow closely,with inundation rates surpassing 8%,while agricultural land experiences comparatively lower inundation rates,exceeding 4%.The results underscore the importance of prioritizing measures to mitigate extreme rainfall events,particularly those exceeding the 99th percentile during flood seasons.By providing decision support grounded in empirical data and advanced modeling techniques,the results contribute to enhancing pluvial flood prevention and mitigation strategies to local government.
作者
胡恒智
董强
辛辰
沈涣焕
温家洪
HU Hengzhi;DONG Qiang;XIN Chen;SHEN Huanhuan;WEN Jiahong(Shanghai Business School,Shanghai 200235,China;Key Laboratory of Cities’Mitigation and Adaptation to Climate Change in Shanghai,China Meteorological Administration,Shanghai 200030,China;Shanghai Customs College,Shanghai 201204,China;Shanghai Normal University,Shanghai 200234,China;Shanghai Central Meteorological Observatory,Shanghai 200030,China)
出处
《自然灾害学报》
CSCD
北大核心
2024年第3期28-38,共11页
Journal of Natural Disasters
基金
上海城市气候变化应对重点开放实验室开放基金课题
国家社科基金青年项目(19CZS077)。
关键词
汛期降雨
降雨阈值
城市内涝
承灾体暴露
flood season rainfall
rainfall threshold
urban waterlogging
exposure of elements at risk
