Wildfires can have strong negative effects on soil and water resources, especially in headwater areas. The spatially explicit OpenLISEM model was applied to a burned catchment in southern Portugal to quantify the individual and combined impacts of wildfire and rainfall on hydrological and erosion processes. The companion paper has calibrated and assessed model performance in this area before and after a fire. In this study, the model was applied with design storms of six different return periods (0.2, 0.5, 1, 2, 5, and 10 years) to simulate and evaluate pre- and post-wildfire hydrological and erosion responses at the catchment scale. Our results show that rainfall amount and intensity played a more important role than fire occurrence in the catchment discharge and sediment yields. Fire occurrence was found to be an important factor for peak discharge, indicating that high post-fire hydro-sedimentary responses are frequently related to extreme rainfall events. The results also suggest a partial shift from runoff to splash erosion after fire, especially for higher return periods. This can be explained by increased splash erosion in burned upstream areas saturating the sediment transport capacity of surface runoff, limiting runoff erosion in downstream areas. Therefore, the pre-fire erosion risk in the croplands of this catchment was partly shifted to a post-fire erosion risk in upper slope forest and natural areas, especially for storms with lower return periods, although erosion risks in croplands were important both before and after fires. These findings have significant implications to identify areas for post-wildfire stabilization and rehabilitation, which is particularly important given the predicted increase in the occurrence of fires and extreme rainfall events with climate change.

野火会对土壤和水资源产生强烈的负面影响，尤其是在源头地区。空间明确的 OpenLISEM 模型被应用于葡萄牙南部的一个被烧毁的集水区，以量化野火和降雨对水文和侵蚀过程的单独和综合影响。配套论文在火灾前后校准和评估了该区域的模型性能。在本研究中，该模型应用于六个不同重现期（0.2、0.5、1、2、5 和 10 年）的设计风暴，以模拟和评估流域尺度上的野火前后水文和侵蚀响应。我们的研究结果表明，降雨量和强度在集水区流量和沉积物产量方面比火灾发生起更重要的作用。发现火灾发生是峰值流量的重要因素，表明火灾后的高水沉积反应经常与极端降雨事件有关。结果还表明，火灾后部分地从径流转变为飞溅侵蚀，尤其是在较高的重现期。这可以解释为上游地区被烧毁的飞溅侵蚀增加，使地表径流的泥沙输送能力饱和，限制了下游地区的径流侵蚀。因此，该流域农田的火灾前侵蚀风险部分转移到了上坡森林和自然区域的火灾后侵蚀风险，特别是对于重现期较短的风暴，尽管农田的侵蚀风险在之前和之前都很重要。火灾后。