Time-dependent Effects of Wildfire Ash and Root Decay on Hydrologic Behavior and Shallow Landslide Susceptibility of Wildfire-Burnt Slopes

野火灰烬和根腐烂对野火烧毁斜坡的水文行为和浅层滑坡敏感性的时间依赖性影响

基本信息

批准号：
1932129
负责人：
Idil Akin
金额：
$ 19.63万
依托单位：
Washington State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2022-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1932129&HistoricalAwards=false
关键词：
Time dependent Effects Wildfire Ash

项目摘要

An increased incidence of wildfires combined with high-intensity storms due to climate change has increased the wetting-induced shallow landslide susceptibility of hillslopes. Post-wildfire landslides and debris flows in recent years in the Western US have caused dozens of fatalities and tremendous economic loss. This project will deliver a framework specific to wildfire-burnt slopes for analyzing shallow landslide susceptibility of hillslopes with time. The new framework could be used to identify critical slopes and prevent catastrophic events that threatens human life, infrastructure, or natural resources. The goal of this project is to understand why and how the shallow landslide susceptibility of wildfire-burnt slopes changes with time and saturation due to root decay and transport of wildfire ash. A hillslope will be instrumented with suction and water content sensors immediately after a wildfire to determine the evolution of water retention behavior over time. Field samples will be collected monthly and scanned using X-ray computed tomography (XCT) to quantify macropore volume over time. The decay rate of fine roots will be quantified using laboratory-controlled burn experiments and XCT scans. The migration of wildfire ash into soil will be identified through saturated hydraulic conductivity tests. A suction-based slope stability analysis will be used to evaluate the change in the shallow landslide susceptibility of a wildfire-burnt slope with time and saturation. The understanding generated in the proposed research will be the first step toward forming a novel and complete framework specific to post-wildfire slope stability analysis as a function of time and saturation.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.

由于气候变化而引起的高强度风暴的发病率增加增加了润湿引起的山坡易感性。近年来，美国西部的野火滑坡和碎屑流动造成了数十人死亡和巨大的经济损失。该项目将提供一个针对野火燃烧的斜坡的框架，用于分析随着时间的推移，山坡的浅水滑坡敏感性。新框架可用于识别关键斜坡并防止威胁人类生命，基础设施或自然资源的灾难性事件。该项目的目的是了解野火燃烧的斜坡的浅滑坡易感性以及如何随着野火灰的根腐烂和运输而随时间和饱和而变化。野火后，将立即用吸力和水分含量传感器来仪器，以确定剩时间的保留行为的演变。将每月收集现场样品，并使用X射线计算机断层扫描（XCT）进行扫描，以量化大孔体积。细根的衰减率将使用实验室控制的烧伤实验和XCT扫描来定量。将通过饱和的水力传导率测试来鉴定野火灰分进入土壤的迁移。基于抽吸的斜率稳定性分析将用于评估随时间和饱和度野火烧伤坡度的浅滑坡敏感性的变化。拟议的研究中产生的理解将是建立特定于野外斜坡稳定性分析的新颖而完整的框架作为时间和饱和的函数的第一步。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的审查标准来评估值得通过评估来支持的。