Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA.
Department of Earth and Environmental Sciences, University of Michigan Ann Arbor, Ann Arbor, MI, USA.
Nat Commun. 2023 Jun 29;14(1):3814. doi: 10.1038/s41467-023-39095-z.
Wildfire alters the hydrologic cycle, with important implications for water supply and hazards including flooding and debris flows. In this study we use a combination of electrical resistivity and stable water isotope analyses to investigate the hydrologic response during storms in three catchments: one unburned and two burned during the 2020 Bobcat Fire in the San Gabriel Mountains, California, USA. Electrical resistivity imaging shows that in the burned catchments, rainfall infiltrated into the weathered bedrock and persisted. Stormflow isotope data indicate that the amount of mixing of surface and subsurface water during storms was similar in all catchments, despite higher streamflow post-fire. Therefore, both surface runoff and infiltration likely increased in tandem. These results suggest that the hydrologic response to storms in post-fire environments is dynamic and involves more surface-subsurface exchange than previously conceptualized, which has important implications for vegetation regrowth and post-fire landslide hazards for years following wildfire.
野火改变了水文循环，对包括洪水和泥石流在内的供水和灾害都有重要影响。在这项研究中，我们使用电阻率和稳定水同位素分析相结合的方法，研究了美国加利福尼亚州圣加布里埃尔山脉 2020 年山猫火灾期间三个流域在风暴期间的水文响应：一个未燃烧，两个燃烧。电阻率成像表明，在燃烧的流域中，降雨渗入风化的基岩并持续存在。风暴流同位素数据表明，尽管火灾后流量增加，但所有流域在风暴期间地表水和地下水混合的量都相似。因此，地表径流和入渗可能同时增加。这些结果表明，火灾后环境中对风暴的水文响应是动态的，涉及到比以前概念化的更多的地表水-地下水交换，这对植被再生和火灾后多年的滑坡灾害都有重要影响。
