CAREER: Field-scale quantification of dynamic physical properties in shrink-swell soils for improved hydrological prediction

职业：对收缩膨胀土壤的动态物理特性进行现场规模量化，以改进水文预测

• 批准号: 2337711
• 负责人: Briana Wyatt
• 金额: $ 68.01万
• 依托单位: Texas A&M AgriLife Research
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-08-01 至 2029-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2337711&HistoricalAwards=false
• 关键词: CAREER; Field; scale; quantification; dynamic

Shrink-swell soils are clayey soils that expand when wetting and shrink when drying. Though these soils account for only 2% of soil globally, they have a disproportionately large impact on water quantity and quality due to their shrink-swell properties, which lead to the formation of cracks that in turn strongly influence key hydrologic processes including water and contaminant transport, infiltration, runoff, and plant water use. Currently, there are no ways of predicting the cracking behavior of these soils or including the effects of these cracks in model simulations. The goal of this research is to improve our ability to measure and predict crack formation in shrink-swell soils, with the ultimate goal of improving models of water flow in soils. This will allow us to better manage and predict the movement of water and pollutants within the environment. In addition, the project will include training opportunities for K-12 teachers to learn about soil science activities and lessons, with the goal of attracting students to the field at a young age.To date, the dynamic physical properties of shrink-swell soils have not been adequately quantified beyond individual sites. Further, theoretical models describing the soil water content-bulk density relationship depend on empirical parameters that lack physical meaning. To address this gap, this project will integrate multiple proven, non-invasive geophysical measurement types at several locations to allow for the accurate field-scale quantification of the soil water content-bulk density relationship. The goal of the proposed research is to improve understanding of and ability to quantify dynamic properties of shrink-swell soils at the field scale by providing a physically-based, non-site-specific representation of the soil water content-bulk density relationship. This objective will be reached using the following objectives: 1) Quantify the relationship between soil moisture and bulk density at the field scale in shrink-swell soils at multiple sites, 2) Quantify the number and size of soil cracks based on surface and subsurface imagery, and 3) Produce field-scale estimates of effective soil hydraulic parameters for characterizing soil shrinkage, swelling, and crack development. The educational objectives of the proposed work are to 1) Broaden participation in soil and Earth sciences by hosting multiple train-the-trainer soil science education workshops for K-12 educators, and 2) incorporate project findings into an existing open-source introductory soil physics textbook. This research will provide a physically-based theoretical model of the soil water content-bulk density relationship at the field scale and lay a foundation for the integration of that model into existing numerical models. This will allow for the dynamic representation of the presence and size of cracks in areas with shrink-swell soils, improving estimates of infiltration, surface runoff, and soil water storage.This project is co-funded by the Hydrologic Sciences and Education and Human Resources programs in NSF's Division of Earth Sciences.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.

收缩膨胀土壤是粘土质土壤，湿润时膨胀，干燥时收缩。尽管这些土壤仅占全球土壤的 2%，但由于其收缩膨胀特性，它们对水量和水质产生了不成比例的巨大影响，导致裂缝的形成，进而强烈影响包括水和污染物在内的关键水文过程运输、渗透、径流和植物用水。目前，还没有方法可以预测这些土壤的开裂行为或在模型模拟中包含这些裂缝的影响。这项研究的目标是提高我们测量和预测收缩膨胀土壤中裂缝形成的能力，最终目标是改进土壤中的水流模型。这将使我们能够更好地管理和预测环境中水和污染物的移动。此外，该项目还将包括为 K-12 教师提供学习土壤科学活动和课程的培训机会，目的是吸引年轻的学生进入该领域。迄今为止，收缩膨胀土壤的动态物理特性已经除了个别站点之外，尚未得到充分量化。此外，描述土壤含水量-堆积密度关系的理论模型依赖于缺乏物理意义的经验参数。为了弥补这一差距，该项目将在多个地点整合多种经过验证的非侵入性地球物理测量类型，以便对土壤含水量与堆积密度关系进行准确的现场规模量化。拟议研究的目标是通过提供基于物理的、非特定地点的土壤含水量-堆积密度关系的表示，提高对现场尺度收缩膨胀土壤动态特性的理解和量化能力。该目标将通过以下目标来实现：1) 量化多个地点收缩膨胀土壤现场尺度的土壤湿度和容重之间的关系，2) 根据地表和地下图像量化土壤裂缝的数量和大小，和 3) 产生有效土壤水力参数的现场规模估计，以表征土壤收缩、膨胀和裂缝发展。拟议工作的教育目标是 1) 通过为 K-12 教育工作者举办多个培训师培训土壤科学教育研讨会来扩大对土壤和地球科学的参与，以及 2) 将项目发现纳入现有的开源介绍性土壤中物理教科书。本研究将为现场尺度的土壤含水量-容重关系提供基于物理的理论模型，并为该模型与现有数值模型的集成奠定基础。这将能够动态地表示收缩膨胀土壤区域中裂缝的存在和大小，从而改进对渗透、地表径流和土壤储水量的估计。该项目由水文科学、教育和人力资源部共同资助该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。