研究人员通过分析2002至2021年的全球卫星数据发现，当持续干旱快速转变为闪电式干旱（flash drought）时，会形成"超易燃"状态，对野火强度和传播产生显著影响[1]。在这种复合干旱条件下，野火规模相比正常条件扩大65%，比单独标准干旱状态下大21%；火灾传播速度提高35%，燃烧时间延长19%[1]。
从干旱发生到野火爆发的时间间隔也存在显著差异[1]。复合干旱条件平均间隔为72天，而闪电式干旱仅需17天，标准干旱则为56天[1]。南美洲、非洲草原、澳大利亚北部和美国西部等地受到闪电式干旱的极端影响最为严重[1]。随着全球气温上升，这种复合干旱现象日益频繁[1]。
Researchers analyzing two decades of global satellite imagery have identified a particularly dangerous weather phenomenon in which rapid droughts—known as flash droughts—dramatically accelerate wildfire spread and severity.[1] When sustained dry conditions abruptly transition into flash droughts, they create what scientists describe as a "super-flammable" landscape state.[1]
The study, which examined data from 2002 to 2021, quantified the amplified fire risk associated with these combined drought conditions.[1] Wildfires under combined drought circumstances spread 35% faster than normal and burn areas 65% larger than fires occurring under standard conditions.[1] Additionally, fires in combined drought scenarios are 21% more extensive than those during standard drought alone, and flames persist 19% longer.[1] The timeline between drought onset and fire ignition also varies significantly: combined droughts average 72 days before fire erupts, whereas flash droughts alone require only 17 days, compared to 56 days for standard droughts.[1]
The heightened vulnerability is geographically concentrated in several regions.[1] South America, African grasslands, northern Australia, and the western United States experience the most extreme manifestations of this intensified fire risk.[1] As global temperatures continue to rise, these flash drought events are becoming increasingly frequent, intensifying the threat to fire-prone landscapes worldwide.[1]
