EAPSI: Understanding the pre-conditioning effects of solar radiation and precipitation on post-wildfire erosion

美国各地的野火正在增加，与火灾相关的危险并没有在火灾扑灭后结束。燃烧过的土壤比普通的森林土壤更容易受到侵蚀，因此野火后的第一场雨可能会产生灾难性的侵蚀。为了预测哪里会发生最严重的侵蚀，我们必须了解不同的土壤在燃烧后是如何侵蚀的。这项研究将探讨景观干燥度（降水和辐射的函数）是否可以用作火灾后侵蚀的预测因子。 这项研究将调查干旱土壤的发展对当地补丁的山脉是否会影响土壤侵蚀力，如果干旱土壤的优先侵蚀导致山区不对称在很长一段时间。这些结果可以更好地预测野火后的侵蚀。这项研究将在澳大利亚墨尔本大学的全球野火后侵蚀研究专家加里谢里丹博士的监督下进行。这项研究将使用遥感图像和地形数据来计算澳大利亚维多利亚山脉的干旱指数。绘制干旱指数图将有效地确定干旱土壤可能形成的地区。实地工作将包括测量最近被绘制为干旱土壤的被烧毁地区的土壤特性，我们将与从非干旱地区获得的样本进行比较。在实地考察期间，我们将通过测量土壤的入渗能力、土壤抗剪强度和土坑中基岩以上的土壤总深度来测试现场土壤水文特性。将进行数值模拟，以确定优先侵蚀将如何影响长期地貌山坡演变的一个经常被烧毁的景观。这个NSF EAPSI奖是与澳大利亚科学院合作资助的。

Wildfire is increasing across the United States, and the hazards associated with fire do not end once the fire is extinguished. Burned soils are more susceptible to erosion than regular forest soils, therefore the first rains after a wildfire can generate catastrophic erosion. To predict where the most severe erosion will occur, we must understand how different soils erode after they are burned. This research will explore if landscape aridity (a function of precipitation and radiation) can be used as a predictor of post-fire erosion. This study will investigate if arid soil development on local patches of a mountain range will influence soil erosivity and if the preferential erosion of arid soils leads to mountain asymmetry over long time periods. The results could lead to better predictions of post-wildfire erosion. This research will be conducted under the supervision of Dr. Gary Sheridan, a global expert on the study of post-wildfire erosion, at the University of Melbourne in Australia. This research will use remote sensing imagery and topographic data to calculate the aridity index across a mountain range in Victoria, Australia. Mapping of the aridity index will effectively delineate where arid soils are likely to form. Fieldwork will involve measurements of soil properties in recently burned areas that were mapped as arid soils, which we will compare with samples obtained from non-arid zones. During the field campaign, we will test in-situ soil hydrologic properties by measuring the water infiltration capacity, the soil shear strength, and the total soil depth above bedrock in soil pits. Numerical modeling will be performed to determine how preferential erosion will effect long-term geomorphic hillslope evolution of a frequently burned landscape. This NSF EAPSI award is funded in collaboration with the Australian Academy of Science.