福建省台风降雨的小时尺度响应特征

基于近5 a登陆福建沿海地区的台风最佳路径,采集台风登陆地区在台风登陆前后3 d(总计7 d)1 747个气象监测站的降雨时程数据.通过识别提取台风登陆区域的降雨特征,在小时时间尺度上,比较研究各登陆区域台风降雨雨型、累积降雨量时程响应特征、峰值降雨强度以及降雨的时间尺度特征.研究结论可为台风暴雨型滑坡灾变机理的数值模拟及模型实验提供重要借鉴,为东南沿海台风暴雨型滑坡的防灾减灾工作以及在更小时间尺度上进行滑坡灾害临滑预警提供理论基础.

Hourly time scale response patterns of typhoon rainfall in Fujian Province

Based on the best track of typhoons that landed in the coastal areas of Fujian in the past five years, this paper collected the rainfall time history data of 1,747 monitoring stations within 3 days before and after the typhoons landed (a total of seven days). By pre-cleaning abnormal time-series cluster data, the extreme rainfall characteristics of the typhoon landing area were identified. The distribution of extreme typhoon rainfall patterns, cumulative rainfall, peak rainfall intensity, and rainfall duration characteristics in the landing areas were investigated respectively on an hourly time-scale. The research shows that the extreme accumulated typhoon rainfall in Fujian Province is more than 200mm. The typhoon rainfall patterns are a multi-peak mode, where 2-5 peak rainfall intensity points can be found and reach the level of heavy rain(>15mm/h). The occurrence of extreme rainfall caused by typhoon landing will lag or exceed the time of typhoon landing. The time-gap is -4~2 hours, and the total duration of the typhoon rainfall process is relatively short, between 24 and 48 hours. Although the rainfall duration of heavy rainfall only accounts for 15-30% of the total rainfall duration, it contributes 60-80% of the accumulative rainfall. This study provides an important reference for the numerical simulation of rainfall process and similarity model experiments of a landslide triggered by typhoon rainfall; Also, it provides a theoretical basis for disaster prevention and mitigation work in the southeast coastal region, as well as an early warning system of landslide disasters on an hourly time- scale.