Extreme water quality degradation following a catastrophic forest fire
Extreme water quality degradation following a catastrophic forest fire
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DOI：
10.1111/fwb.12548
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发表时间：
2015-12-01
影响因子：
2.7
通讯作者：
van Horn, David J.
中科院分区：
文献类型：
--
作者：
Dahm, Clifford N.;Candelaria-Ley, Roxanne I.;van Horn, David J.
全球变化正在影响美国西部的森林，包括气温上升、融雪提前、雨多雪少、春季和秋季蒸气压不足、森林枯死以及森林火灾频率和严重程度增加。 2011 年，美国新墨西哥州中部发生了一场灾难性森林火灾（Las Conchas 火灾），烧毁面积约 100 公顷。 634公里(2)，c。 46% 的火灾为严重或中等强度。美国国家海洋和大气管理局 (NOAA) 的下一代雷达数据 (NEXRAD) 用于将烧伤疤痕中发生的降水事件与格兰德河观测到的极端水质偏差联系起来。在四个地点，现场传感器捕获了水温、电导率、pH 值、浊度和溶解氧对火灾后洪水事件的响应。烧伤疤痕的径流导致浊度峰值（达到 2500 NTU）、溶解氧下降（下降到 0.0mgL(-1)）、pH 下降（高达 0.75 单位）和电导率变化（增加和减少）。这些水质偏差向下游延伸了至少 50 公里，对这条为城市和农业供水的重要河流的生态系统健康产生了重大影响。严重的森林火灾和森林枯死导致的森林流域突然发生的巨大变化很可能是全球变化对美国西部溪流和河流生态系统最严重的影响之一。
Global change is impacting the forests of the western United States through rising temperatures, earlier snowmelt, more rain and less snow, greater vapour pressure deficits in spring and autumn, forest dieback and increasing forest fire frequency and severity. A catastrophic forest fire (Las Conchas fire) occurred in central NM, USA, in 2011 burning c. 634km(2) with c. 46% of the fire being of severe or moderate intensity. National Oceanic and Atmospheric Administration (NOAA) next-generation radar data (NEXRAD) were used to link precipitation events occurring in the burn scar to extreme water quality excursions observed in the Rio Grande. At four sites, in situ sensors captured the response of water temperature, specific conductance, pH, turbidity and dissolved oxygen to flood events following the fire. Runoff from burn scars caused turbidity peaks (to 2500 NTU), dissolved oxygen sags (to 0.0mgL(-1)), pH sags (up to 0.75 units) and conductivity changes (both increases and decreases). These water quality excursions extended at least 50km downstream, with significant implications for the ecosystem health of this crucial river that supplies water to cities and agriculture. Sudden, dramatic changes to forested catchments from severe forest fires and forest dieback are very likely to be among the strongest impacts of global change on stream and river ecosystems throughout the western United States.