南方高度城市化地区极端降雨特征分析及阈值确定——以深圳市为例

研究南方高度城市化地区极端气候变化规律,定义极端降雨事件的阈值并对地域风险进行评估,对于完善区域"三防"指挥系统的预报预警方案,应对气候变化和快速城市化过程中的极端暴雨内涝灾害风险,具有重要的现实意义。以深圳市为例,在收集统计2000-2015年暴雨灾害事件和相应的多个站点降雨数据基础上,采用模糊识别、PCI等方法分析了该区域的降雨雨型、集中度特征,并采用百分位法对深圳市极端降雨阈值进行了分析和计算。结果表明:造成深圳市内涝的大部分降雨主要是单峰型;均匀大量降雨是内涝主要产生原因;大鹏新区的降雨阈值最高,降雨阈值空间分布图从东往西呈逐渐减少趋势;深圳市极端降雨阈值为降雨频率P=1%的降雨值。

Analysis and determination of extreme precipitation threshold in highly urbanized areas of Southern China:A case from Shenzhen

It is very important to study the extreme weather variations, to define the threshold of extreme rainfall event and to evaluate the risk of internal water-logging for highly urbanizing areas in Southern China for improving the forecasting and early warning schemes in the command system, and dealing with the extreme rainstorms and water-logging disasters in the courses of climate change and rapid urbanization. Taking Shenzhen as an example, based on data collection of the rainstorm events in Shenzhen from 2000 to 2015 and the corresponding rainfall data from several sites, the fuzzy identification method and PCI were used to analyze the rainfall pattern and rainfall concentration in the region. Also, the Shenzhen extreme rainfall threshold has been analyzed and calculated using the percentile method. The results showed that the single-peak type rainfalls were main rainfall type which caused water-loggings of Shenzhen; the main cause of waterlogging was uniform heavy rainfall; the highest rainfall threshold was located in the Dapeng New Area and the spatial distribution of rainfall thresholds decreased from the east to the west; the extreme rainfall threshold of Shenzhen was the rainfall with frequency of 1%.