Collaborative Research: RAPID: Investigating the magnitude and timing of post-fire sediment transport in the Texas Panhandle

最近，德克萨斯州历史上最大的野火烧毁了超过110万英亩（4450平方公里）的土地，摧毁了整个德克萨斯州狭长地带的牲畜、庄稼、野生动物、房屋和牧场基础设施。野火对沉积物运输的影响已经得到了很好的研究，结果表明，在随后的降雨事件中，植被的缺乏和被烧毁土壤的疏水性特征创造了加剧地表流动的条件，并可能调动大量细沉积物并引发泥石流。然而，对火灾后水文和地貌过程的理解大多来自陡峭（30度）和森林景观。德克萨斯州狭长地带低坡度（1-10度）的草地和灌木丛景观的火灾后过程尚不清楚。这个项目将为管理联邦政府分类的重要栖息地提供重要数据，这些栖息地是一种濒危鱼类的栖息地。该项目支持德克萨斯州三家西班牙裔服务机构的本科生研究。这项研究对于了解灌木林火灾后沉积物迁移的幅度和时间至关重要。这项工作的一个主要贡献将是收集像德克萨斯州狭长地带这样的低坡度环境中火灾后沉积物运输的第一次测量。对泥沙颗粒大小和风化层厚度的测量将说明泥沙输运率在多大程度上受到陆上水流或泥沙可利用性施加的应力的限制。该项目还将限制植被作为低坡度环境中间歇性火灾介导的储存场所的重要性。最后，对加拿大河和梅雷迪思湖悬浮沉积物的测量将限制从山坡和支流到梅雷迪思湖沉积物汇的细沉积物的运输时间尺度。该奖项反映了美国国家科学基金会的法定使命，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。

The largest wildfires in Texas history recently burned more than 1.1 million acres (4,450 square kilometers), and have devastated livestock, crops, wildlife, homes, and ranching infrastructure across the Texas Panhandle. The effects of wildfire on sediment transport are well studied, and indicate that the absence of vegetation and hydrophobic characteristics of burned soils create conditions that intensify overland flow during subsequent rain events and can mobilize large volumes of fine sediment and initiate debris flows. However, much of this understanding of post-fire hydrologic and geomorphic processes is derived from steep (30 degrees) and forested landscapes. Post-fire processes in the lower-slope (1–10 degrees) grassland and shrubland landscapes of the Texas Panhandle are unknown. This project will contribute important data for management of federally classified critical habitat that hosts an endangered fish species, the peppered chub. The project supports undergraduate research at three Hispanic Serving Institutions across Texas.This study is crucial for understanding the magnitude and timing of post-fire sediment transport in shrublands. A major contribution of this work will be the collection of the first post-fire sediment transport measurements in low-sloping environments like the Texas Panhandle. Measurements of sediment grain size and regolith thickness will inform the degree to which sediment transport rates are limited by stress exerted by overland flow or sediment availability. This project will also constrain the importance of vegetation as an intermittent fire-mediated storage site in low-sloping environments. Finally, measurements of suspended sediment in the Canadian River and Lake Meredith will constrain the transport timescales for fine sediment from hillslopes and tributaries to reach the sediment sink of Lake Meredith.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.