Revealing Soil Hydraulic Properties

了解土壤中的水储存和运动对于解决广泛的农业，工程和环境问题至关重要。控制水分储存和运动的土壤水力特性在时间和空间上变化很大，并且难以用现有技术测量。本研究旨在开发使用更容易测量的土壤热和电特性值来估计土壤水力特性值的模型。这些模型可以与现有的测量技术一起使用，由科学家和工程师致力于解决与食品，能源和环境安全相关的各种国家和全球挑战。该项目还将为一名博士后学者以及研究生和本科生研究人员提供培训机会。土壤水力特性控制着土壤含水量的转变，从而推动陆地水文循环中的无数过程。因此，测量和预测土壤水力特性的能力至关重要，但仍然是水文科学的主要限制。由于土壤结构对水力、电和热特性的相关影响，可以假设更容易测量的土壤电和热特性可以一起用作替代物来确定水力特性。拟议的调查旨在更好地了解土壤水力，电气和热性能之间的基本关系，为完整的土壤，并制定方法，在现场估计土壤水力性能的替代电气和热性能数据。热时域反射计传感器将被用来测量土壤的电，热和水力特性的完整和重新包装的样品从外地网站在北卡罗来纳州和爱荷华州，以及在现场测量。收集的数据集将支持研究团队以及更广泛的研究社区的建模工作。 如果成功的话，拟议的工作将立即使现场水力特性的确定，目前不可能与任何现有的方法。由于基本的测量是热和电特性，基本方法也可以扩展到一系列传感平台。该项目将包括研究生和本科生的研究经验（REU）培训机会，并为非附属研究人员的土壤热和电性能的测量短期课程。该奖项旨在促进对基本水文过程的发现和理解，同时促进不同学生和其他研究人员的教学、培训和学习。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。

Understanding of water storage and movement in soil is critically important to solve a wide range of agricultural, engineering, and environmental problems. The soil hydraulic properties that control water storage and movement are highly variable in time and space, and difficult to measure with existing technologies. This research seeks to develop models that use more easily-measured soil thermal and electrical property values to estimate soil hydraulic property values. These models can be used with existing measurement technologies by scientists and engineers working to address a wide range of national and global challenges related to food, energy, and environmental security. The project will also provide training opportunities for a post-doctoral scholar, and both graduate and undergraduate student researchers.Soil hydraulic properties control transitions in soil water content, thereby driving myriad processes in the terrestrial hydrologic cycle. Capability to measure and predict soil hydraulic properties is thus critically important, yet remains a major limitation for the hydrologic sciences. Owing to relatable influences of soil structure on hydraulic, electrical, and thermal properties, it is hypothesized that more-easily measured soil electrical and thermal properties can be used together as surrogates to determine hydraulic properties. The proposed investigation seeks both to better understand fundamental relationships among soil hydraulic, electrical, and thermal properties for intact soils, and to develop approaches for in situ estimation of soil hydraulic properties from surrogate electrical and thermal property data. Thermo-time domain reflectometer sensors will be used to measure soil electrical, thermal, and hydraulic properties of intact and repacked samples from field sites in North Carolina and Iowa, as well as for in situ measurements in the field. The collected dataset will support modeling efforts for the research team as well as the broader research community. If successful, the proposed work will immediately enable in situ hydraulic property determinations that are not currently possible with any existing approaches. And because the fundamental measurements are thermal and electrical properties, the basic approach can also potentially be extended to a range of sensing platforms. The project will include both graduate and undergraduate research experience (REU) training opportunities, and a short-course for non-affiliated researchers on the measurement of soil thermal and electrical properties. The proposed effort aims to advance discovery and understanding for fundamental hydrological processes while promoting teaching, training, and learning for diverse students and other researchers.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.