Collaborative Research: Effects of Hydrologic Processes on In Situ Stress Transients

了解水如何在景观中移动和储存是水文研究中最普遍的主题之一，但水循环的重要方面仍然知之甚少。拟议的研究项目将解决目前在描述水循环方面的局限性，并由两个相关假设驱动：1。水含量的水文重要变化足以引起原位应力状态的可测量变化。2. 地应力的瞬态变化可用于估算多尺度的水文通量和库容变化。这项调查将发展概念和数值方法来分析与地应力变化有关的水文过程，以及测量这些变化的仪器和现场技术。将开发新的现场仪器来测量总应力和有效应力变化，目标分辨率为1pa。在南卡罗来纳州克莱姆森附近进行的概念验证现场测试将比较高分辨率应力测量与含水量和其他过程的瞬态变化。更严格的实地试验将在堪萨斯州进行，该方法将用于估计阿肯色河沿岸地区由蒸发蒸腾和其他影响引起的质量变化。对渗透层和饱和层孔隙弹性的理论分析将用于评估含水量变化对应力的影响，以及各种其他潜在的竞争效应，包括气压变化、地下地质、潮汐、地下水提取、区域水平流、地表蓄水、交通、风、温度等。新的领域方法是水文学科学发现的催化剂，而拟议的研究的智力价值在于它有可能成为这种发现的催化剂。这项调查将为新的实地技术、理论分析和仪器提供科学基础，这些技术将提高在小于1米到大于100米的尺度上表征水文循环（ET、土壤湿度变化、补给、暴雨流等）关键方面的能力。为这个项目开发的技术将产生广泛的影响，提供可用于改进遥感仪器和算法的验证和校准的多尺度数据；雪堆或冰川融化或积累的估计；评估侵蚀率或沉积物沉积率；构造应变的降噪与分辨；碳储量评估；灌溉调度方法；了解森林火灾引起的大规模变化，以及相关变化。

Understanding how water moves and is stored within the landscape is among the most pervasive themes of hydrological research, but important aspects of the water cycle remain poorly known. The proposed research project will address current limitations in characterizing the water cycle and is motivated by two related hypotheses: 1. Hydrologically important changes in water content are sufficient to cause measurable changes in the in situ state of stress. 2. Transient changes of in situ stress can be used to estimate hydrologic fluxes and changes in storage over multiple scales.This investigation will develop conceptual and numerical methods for analyzing hydrologic processes associated with changes of in situ stress as well as instruments and field techniques for measuring these changes. New field instrumentation will be developed to measure total and effective stress changes with a target resolution of 1 Pa. A proof-of-concept field test near Clemson, SC will compare high resolution stress measurements to transient changes in water content and other processes. A more rigorous field test will take place in Kansas, where the method will be used to estimate changes in mass resulting from evapotranspiration and other effects in a riparian zone along the Arkansas River. Theoretical analyses of poroelasticity in the vadose and saturated zones will be used to evaluate how stresses are affected by changes in water content, as well as a variety of other potentially competing effects including barometric pressure change, subsurface geology, earth tides, ground water extraction, regional horizontal flows, surface impoundments, traffic, wind, temperature, etc. New field approaches are catalysts for discovery in hydrologic sciences, and the intellectual merit of the proposed investigation is that it has the potential to be such a catalyst for discovery. The investigation will provide the scientific basis for new field techniques, theoretical analyses and instrumentation that will advance the ability to characterize key aspects of the hydrological cycle (ET, change in soil moisture, recharge, stormflow, etc.) over scales from less than 1 m to greater than 100 m. The techniques developed for this project will have broad impacts by providing multi-scale data that can be used to improve: validation and calibration of remote sensing instruments and algorithms; estimates of melting or accumulation of snow pack or glaciers; assessment of rates of erosion or sediment deposition; reduction of noise and resolution of tectonic strain; assessment of rates of carbon storage; methods for scheduling irrigation; understanding mass changes resulting from forest fires, and related.