山东省区域性暴雨事件时空变化特征及个例分析——以台风“利奇马”暴雨过程为例

Temporal and spatial variation characteristics and case analysis of regional rainstorm events in Shandong Province--taking typhoon“Lekima”rain process as an example

利用山东省123个国家地面气象观测站1961—2019年逐日、逐小时降水量资料,在定义区域性暴雨事件的基础上,选取最大过程降水量、最大日降水量、最大1 h降水量、暴雨站数和过程持续时间作为评估指标,构建山东省区域暴雨事件和单站暴雨事件综合强度评估模型。针对判别出的545次区域暴雨事件,进行时空特征分析。结果表明,山东省区域暴雨事件发生次数呈现波动变化、缓慢下降趋势,但平均综合强度呈现缓慢上升趋势,且2011年以来上升趋势显著。区域暴雨事件集中发生于7、8月,其中以7月发生次数最多,8月平均综合强度最高。降雨中心主要分布于半岛东部和鲁南地区,不同时段分布配置略有不同,但差别不大。历史回算结果与灾情记录一致性较高,以台风“利奇马”暴雨过程为例,通过分县灾情验证表明暴雨事件综合评估模型评估结果较为合理,尤其对历史重大暴雨事件吻合效果理想。

By using the daily and hourly precipitation data from 123 national meteorological observatories in Shandong Province from 1961 to 2019,the maximum process precipitation,maximum daily precipitation,maximum hour precipitation,number of rainstorm stations and process duration were selected as evaluation indicators based on the definition of regional rainstorm events,a comprehensive intensity assessment model for regional rainstorm events was built.The 545 regional rainstorm events were determined to analyzethe spatial and temporal characteristics.Results show that the number of regional rainstorm events in Shandong Province present fluctuations and slow declines,but the average comprehensive intensity present a slow upward trend,and the upward trend since 2011 is significant.The regional heavy rain events often occur in July and August,with the most occurrences in July and the highest overall intensity in August.The rainfall center is mainly distributed in the eastern part of the peninsula and in the southern Shandong area.The distribution configuration is slightly different at different times,but it is not significant.The historical events identification results are consistent with the disaster record.Taking typhoon“Lekima”storm as an example,the case analysis shows that the assessment results of the comprehensive evaluation model of the rainstorm event are relatively reasonable,especially for the historical heavy rain events.