Vegetation-Rainfall interactions reveal how climate variability and climate change alter spatial patterns of wildland fire probability on Big Island, Hawaii.
Vegetation-Rainfall interactions reveal how climate variability and climate change alter spatial patterns of wildland fire probability on Big Island, Hawaii.
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DOI：
10.1016/j.scitotenv.2018.08.347
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发表时间：
2019-02
期刊：
影响因子：
--
通讯作者：
C. Trauernicht
中科院分区：
文献类型：
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作者：
C. Trauernicht
近几十年来，夏威夷每年被野火烧毁的面积增加了四倍。群岛的新型燃料类型和气候异质性为火灾风险评估和火灾管理带来了重大挑战。使用历史野火记录的基于概率的火灾发生模型为夏威夷等火灾科学投资有限的地区提供了一种评估和归因火灾风险的方法。本研究使用广义加性模型，1)评估夏威夷岛西北象限植被、气候和人为点火对火灾概率的相对贡献；2)比较景观可燃性如何因年际降雨量变化而变化，以及预计的年平均降雨量（MAR）和温度变化。年火灾概率以草地最高，在干旱条件下最高（在450 mm MAR时为0.04），而灌丛（在650 mm MAR时为0.03）和森林（在600 mm MAR时为0.015）。火灾发生前一年的过量降雨增加了草原的火灾风险，从而增加了总体火灾概率，比火灾发生当年的干旱更严重。在预测的气候变化下，该地区的干燥和变暖趋势使火灾概率最大值增加了375%，并将景观可燃性峰值区域转移到更高的海拔。对未来气候的模型预测也表明，到本世纪中叶，景观可燃性将发生最大变化。先前潮湿年份对火灾风险的影响可以改善夏威夷火灾风险的近期预测，而气候预测表明，需要优先考虑高海拔地区高价值自然资源集中的火灾管理。
The area burned annually by wildland fire in Hawaii has increased fourfold in recent decades. The archipelago's novel fuel types and climatic heterogeneity pose significant challenges for fire risk assessment and fire management. Probability-based fire occurrence models using historical wildfire records provide a means to assess and attribute fire risk in regions of the world like Hawaii where investment in fire science is limited. This research used generalized additive models to 1) assess the relative contribution of vegetation, climate, and human-caused ignitions to the probability of fire in the northwest quadrant of Hawaii Island and 2) compare how landscape flammability varies due to interannual rainfall variability versus projected changes in mean annual rainfall (MAR) and temperature. Annual fire probability was highest for grasslands and peaked at drier conditions (0.04 at 450 mm MAR) when compared with shrublands (0.03 at 650 mm MAR) and forest (0.015 at 600 mm MAR). Excess rainfall the year prior to fire occurrence increased fire risk across grasslands, and thus overall fire probability, more so than drought the year that fire occurred. Drying and warming trends for the region under projected climate change increased maximum values of fire probability by as much as 375% and shifted areas of peak landscape flammability to higher elevation. Model predictions under future climate also indicate the largest changes in landscape flammability will happen by mid-Century. The influence of antecedent wet years on fire risk can improve near-term predictions of fire risk in Hawaii while climate projections indicate that fire management will need to be prioritized at upper elevations where high value natural resources are concentrated.