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Full-Text Articles in Physical Sciences and Mathematics
Characterizing Mountainous Bedrock Groundwater Systems Across Gradients In Topography And Lithology In Western Montana, David L. Baude
Characterizing Mountainous Bedrock Groundwater Systems Across Gradients In Topography And Lithology In Western Montana, David L. Baude
Graduate Student Theses, Dissertations, & Professional Papers
Mountain aquifer groundwater systems remain one of the least understood hydrologic systems in upland hydrology. In this study, we aim to characterize bedrock groundwater system dynamics and bedrock-saprolite interactions across a variety of landscape positions and lithology. We investigate groundwater hydraulics, recharge temperature and elevation, residence times, and bedrock recharge rates across two mountainous headwater catchments in west central Montana. We used a suite of environmental tracers (3H, CFCs, SF6, and 4He) and residence time distribution models to estimate groundwater mean residence times over a range of timescales from decades to millennia. Tracers were sampled …
Evaluating The Use Of Environmental Tracers To Reduce Conceptual Model Uncertainty Of Hydrogeologic Models, Andrew Nordberg, Jon Graham, W. Payton Gardner
Evaluating The Use Of Environmental Tracers To Reduce Conceptual Model Uncertainty Of Hydrogeologic Models, Andrew Nordberg, Jon Graham, W. Payton Gardner
Graduate Student Theses, Dissertations, & Professional Papers
Environmental tracer concentrations for CFC12, SF6, and tritium are used in groundwater simulations to assess the ability of these tracers to reduce conceptual model uncertainty due to uncertainty of a site’s geologic and recharge characterization. The resulting groundwater simulations are characterized by site-specific hydrologic and geologic data, and with coordination from a field team with years of knowledge about the site. First-order (conceptual) uncertainty is directly addressed by using a stochastic modeling approach for spatial variability of the proposed subsurface configurations. Simulations of environmental tracer concentrations and water levels are used to assess six alternate conceptual models that are based …
Using Multiple Environmental Tracers To Investigate The Relative Role Of Soil And Deep Groundwater In Stream Water Generation For A Snow-Dominated Headwater Catchment, Isabellah V. Von Trapp
Using Multiple Environmental Tracers To Investigate The Relative Role Of Soil And Deep Groundwater In Stream Water Generation For A Snow-Dominated Headwater Catchment, Isabellah V. Von Trapp
Graduate Student Theses, Dissertations, & Professional Papers
In this study, seasonal fluctuation of environmental tracers in stream flow, soil water, and deep bedrock groundwater were used to constrain the role of deep bedrock groundwater in streamflow generation for a mountainous headwater catchment. Synoptic measurements of stream discharge, 222Rn, specific conductivity and major ion concentrations were measured throughout the water year over a 5 km reach of Cap Wallace Creek in the Lubrecht Experimental Forest, Montana, U.S.A. with the intention of understanding groundwater – surface water interactions across spatial and temporal scales. Stage measurements were continually recorded at seven stilling well locations along the reach. Discharge measurements …