ABSTRACT

We modelled hydrological, hydraulic and habitat suitability changes in a Mediterranean catchment after a wildfire. Gauged pre/post-fire hourly discharges were used to assess actual pre/post-fire hydrological conditions. To remove the weather variability effect, daily pre/post-fire discharges were simulated under the same weather conditions. An eco-hydraulic model was employed to calculate flow velocities, water depths and macroinvertebrate habitat suitability at various discharges across a 165 m long reach. The fire increased the magnitude and frequency of peak velocities and depths by 6.5–475%. Increased post-fire rainfall exacerbated hydrological-hydraulic extremes. However, the short duration of post-fire extremes led to small impacts on the habitat suitability for macroinvertebrates, which were stressed for a maximum 18.4% of the time after the fire (350 days in five years). In small Mediterranean-climate headwaters, after wildfires, less frequent streamflow becomes more frequent, high and of short duration. Macroinvertebrates largely resist such short-term, low-magnitude hydrological-hydraulic changes.

摘要

我们模拟了野火后地中海集水区的水文、水力和栖息地适宜性变化。测量的火灾前/火灾后每小时排放量用于评估实际的火灾前/火灾后水文状况。为了消除天气变化的影响，在相同的天气条件下模拟了火灾前后的每日排放量。采用生态水力模型来计算 165 米长河段不同排放量的流速、水深和大型无脊椎动物栖息地适宜性。火灾使峰值速度和深度的幅度和频率增加了 6.5-475%。火灾后降雨量的增加加剧了水文水力极端情况。然而，火灾后极端事件的持续时间短，对大型无脊椎动物的栖息地适宜性产生了很小的影响，最大压力为 18。火灾后 4% 的时间（五年内 350 天）。在小型地中海气候源头，野火过后，不太频繁的河流流量变得更加频繁、高和持续时间短。大型无脊椎动物在很大程度上抵抗这种短期、低幅度的水文水力变化。