CAREER: Spatial Quantification of Fundamental Mechanisms that Initiate Post-Wildfire Wetting-Induced Shallow Landslides

这个教师早期职业发展（CAREER）奖将探讨如何在森林环境的动态变化，从野火恢复控制燃烧山坡的稳定性对潮湿引起的浅层滑坡随着时间的推移。美国的野火管理策略已经从“扑灭野火”转变为“与野火共存”，这涉及到社区对野火的适应。野火后山体滑坡已被确定为社区适应野火的严重级联风险，但基本的启动机制尚不清楚。目前还没有专门针对野火的方法来评估烧毁山坡的滑坡敏感性。该项目将是开发野火特定框架的第一步，用于分析山坡的稳定性，作为不同强度火灾和不同滑坡机制的时间，饱和度和森林使用实践的函数。该研究将与教育计划相结合，旨在使新一代工程师能够分析和减轻野火后山体滑坡的风险，告知政策制定者，并促进社区对此类风险的教育。本研究的主要研究目标是量化改变机械和水文土壤行为的基本机制，从而在野火后环境中的边坡稳定性。基本机制被假设为受森林系统动力学控制（即，树木损失，再生，灰运动），协同控制吸力应力。为了实现主要的研究目标，将实现以下具体目标：1）量化野火后吸力应力和森林系统动态随时间的推移，2）确定森林系统动态的组成部分的变化函数与吸力应力，和3）评估野火后浅层滑坡的敏感性使用概率的方法。这将需要对野火后环境中的土壤行为进行多尺度调查。该研究计划涉及从原子尺度到山坡尺度的土壤行为测试，并将允许多传感器数据融合。现场和实验室数据将与激光雷达扫描和航空照片的空间数据相结合。沿山坡的吸力应力沿着的空间变异性将作为一个分布函数，并将是一个概率斜坡稳定性模型的输入，用于评估潮湿引起的浅滑坡的敏感性烧山坡。此外，还将通过水蒸气吸附等温线研究吸力应力的吸附分量对土壤持水曲线的依赖性。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) award will explore how dynamic changes in a forest environment that is recovering from a wildfire control the stability of burnt hillslopes against wetting-induced shallow landslides over time. The US wildfire management strategy has changed from “fighting wildfires” to “living with wildfires,” which involves community adaptation to wildfires. Post-wildfire landslides have been identified as a serious cascading risk to community adaptation to wildfires, but the fundamental initiation mechanisms are not yet understood. There is currently no wildfire-specific approach to evaluating the landslide susceptibility of burned hillslopes. This project will be the first step toward developing a wildfire-specific framework for analyzing the stability of hillslopes as a function of time, saturation, and forest use practices for different intensity fires and different landslide mechanisms. The research will be integrated with an education program aiming to place a new generation of engineers in a position to analyze and alleviate the risk of post-wildfire landslides, inform the policy makers, and promote community education about such risks.The primary research objective of this study is to quantify the fundamental mechanisms that change mechanical and hydrologic soil behavior and therefore slope stability in post-wildfire environments. The fundamental mechanisms are hypothesized to be controlled by forest system dynamics (i.e., tree loss, regrowth, ash movement), that synergistically control suction stress. To achieve the primary research objective, the following specific objectives will be achieved: 1) quantify post-wildfire suction stress and forest system dynamics over time, 2) identify the change functions for the components of forest system dynamics in relation to suction stress, and 3) evaluate post-wildfire shallow landslide susceptibility using a probabilistic approach. This will require a multiscale investigation of soil behavior in post-wildfire environments. The research plan involves testing soil behavior from the atomic scale to the hillslope scale and will allow multi-sensor data fusion. Field and laboratory data will be combined with spatial data from LiDAR scans and aerial photographs. The spatial variability in suction stress along the hillslope will be presented as a distribution function and will be an input for a probabilistic slope stability model for evaluating the wetting-induced shallow landslide susceptibility of burned hillslopes. In addition, the dependency of the adsorptive component of suction stress on the soil water retention curve will be investigated through water vapor sorption isotherms. This will improve our understanding of the degree of physicochemical forces on mechanical soil behavior.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.