京津冀地区台风危险性评估——基于Gumbel分布的分析

台风引发的连续暴雨是京津冀地区主要的气象灾害之一,开展台风危险性评估,旨在识别台风灾害高危险区,为京津冀地区台风灾害防灾减灾能力提升和风险管理提供参考。根据1974-2015年间影响京津冀地区的台风资料,选取该地区148个国家气象站点的气象数据,包括最大日降水量、累积降水量及最大风速3个指标。借助Gumbel分布,求出各气象站点5 a、10 a、30 a及50 a一遇水平下的气象指标数值,利用ArcGIS空间插值表征其空间分布,据此评估京津冀地区台风危险性。结果表明,50 a一遇下台风灾害最大日降水最大值为190.62 mm,累积降水量最大值为253.04 mm,最大风速最大值为16.81 m/s。其中北京东南部、天津北部、河北省东南沿海地区和太行山一带的石家庄、邢台、邯郸等地区为高危险区。

Hazard assessment of typhoons affecting the Beijing-Tianjin-Hebei region based on Gumbel distribution

Continuous rainstorm caused by typhoons is one of the major meteorological disasters in the Beijing-Tianjin-Hebei region. This study focused on the hazard assessment of typhoons, identified the high hazard areas,and provided references for the disaster prevention and mitigation capabilities of typhoons in the Beijing-Tianjin-Hebei region. Based on the typhoons that affected the Beijing-Tianjin-Hebei region from 1974 to 2015, spatial variations of precipitation and wind speed are examined using 42 years of data from 148 meteorological stations, and the spatial distribution patterns are depicted by ArcGIS. Gumbel distribution is used to calculate the values of meteorological parameters at the stations under different return periods (RP 5 a, 10 a, 30 a, 50 a). The results show that the maximum daily precipitation is 190.62 mm, the maximum cumulative precipitation is 253.04 mm, and the maximum wind speed is 16.81 m/s (RP=50 a). Southeastern Beijing, northern Tianjin, southeastern coast of Hebei Province, and the Taihang Mountains are the high hazard areas.