Evaluation of Climate-driven Near-surface Soil Moisture Fluctuation in Earthen Transportation Infrastructure

Understanding subsurface hydrologic regimes is key to the design and management of a significant number of transportation infrastructure assets, such as highway and railway embankments. These hydrologic regimes are dictated primarily by climate and soil properties. In the current state-of-the-practice, civil infrastructure is engineered to function based on defined subsurface hydrologic regimes that are based on recurring weather patterns and pre-defined chances of climate extremes. However, weather and subsurface hydrologic records are often limited or unavailable. Additionally, shifts in weather patterns brought about by climate change put vast geotechnical infrastructure assets in risk of unexpected failure. The consequences associated with critical infrastructure failures can be severe, including fatalities, injuries, loss of assets, contamination of groundwater, and/or dislocation of communities. While climatologists have made significant strides in modelling climate and developing climate change prediction models, the effect of climate on subsurface hydrologic regimes lacks practical modeling in geotechnical infrastructure engineering. Accordingly, it is essential to develop methods to facilitate estimation of subsurface hydrologic regimes considering climate change effects on soil-atmosphere interaction. Such methods are necessary for performing engineering analyses and designs for vast infrastructure. That is, to understand weather pattern impacts on soil behavior, and in turn on infrastructures, it is important to be able to adequately parametrize soil-atmosphere interaction mechanisms. This study aims to parameterize soil-atmosphere interaction to analytically describe subsurface hydrologic regimes. The specific objectives of the study include (1) compilation and evaluation of existing data on near-surface soil moisture fluctuation; (2) fundamental assessment of soil-atmosphere interaction using soil column physical models, (3) synthesis and evaluation of existing subsurface soil moisture profile models; (4) development of a design framework for engineering practice; and (5) training of undergraduate research students in civil engineering to partake in applied research during their undergraduate studies and prepare them for the nation’s current challenges.