复合型热带气旋事件及其经济损失时空变化特征

Spatio-Temporal Characteristics of Compound Tropical Cyclone Events and Their Economic Losses

关键词:  复合型热带气旋  直接经济损失  时空变化  极端事件

Key words:  compound tropical cyclones  direct economic losses  spatio-temporal characteristics  extreme events

摘要:

近年来，多个热带气旋(TropicalCyclone，TC)接连影响同一地区并造成严重经济损失的现象频发。以TC路径为中心划定50km影响区，将多个TC影响区在空间上有交叠且影响时间相距不超过10日的事件定义为一个复合型TC事件。基于1949—2022年西北太平洋TC数据集与1984—2022年中国的TC灾情数据，对复合型TC事件进行识别并开展对其经济损失时空变化特征的研究。(1)1949—2022年每年代约有6.9个复合型TC事件发生，不同年代间复合型TC事件频数差异显著，1960s为频发期。全国范围内约14.8%地区受到复合型TC事件影响，除传统易受TC影响地区(如东南沿海)外，中高纬度沿海及邻近内陆地区也暴露于其影响范围内，2010s受影响面积最大。(2)在1984—2022年有复合型TC事件发生的年份中，复合型TC事件产生直接经济损失约占TC总损失的39%，以9.6%(10a)-1的速度增加，表明复合型TC事件的破坏力不断增强。高强度复合型平均经济损失约为低强度复合型的2.2倍。(3)复合型TC事件产生的经济损失明显高于单一TC，灾害叠加效应显著。传统TC受灾区易受高强度复合型影响，中高纬度地区暴露于低强度复合型影响下易产生严重经济损失，需提升防台减灾能力建设。

Abstract:

In recent years, the occurrence of multiple tropical cyclones (TCs) which consecutively impact the same region, resulting in significant economic losses, has become increasingly frequent. This study defines a compound TC event as an occurrence where the 50 km impact zones centered on the tracks of multiple TCs overlap spatially and the temporal interval between their impacts is no more than 10 days. Based on a dataset of Northwest Pacific TCs from 1949 to 2022 and TC disaster data in China from 1984 to 2022, we identify compound TC events and analyze their spatiotemporal characteristics of economic losses. The results indicate that: (1) From 1949 to 2022, an average of approximately 6.9 compound TC events occurred per decade, with significant differences in frequency across decades and a peak during 1960s. About 14.8% of the national territory was impacted by compound TC events, affecting not only traditionally vulnerable areas (such as the southeast coast) but also mid - to high-latitude coastal and adjacent inland regions, with the largest affected area observed in the 2010s. (2) In the years with recorded compound TC events from 1984 to 2022, direct economic losses from these events account for approximately 39% of total TC losses, increasing at a rate of 9.6% per decade, indicating a growing destructiveness of compound TC events. The average economic losses from high-intensity compound TCs were about 2.2 times greater than those of low-intensity compound TCs. (3) Economic losses from compound TC events are significantly higher than those from single TCs, highlighting the pronounced disaster amplification effect. Traditional TC-affected areas are particularly susceptible to high-intensity compound TCs, while mid-latitude regions exposed to low-intensity compound TCs are likely to incur severe economic losses, necessitating improvements in typhoon disaster prevention and mitigation capabilities.