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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Evaluating The Sensitivity Of Crustal Deformation To Bedrock Hydrology In A Mountain Watershed, Brett J. Oliver
Evaluating The Sensitivity Of Crustal Deformation To Bedrock Hydrology In A Mountain Watershed, Brett J. Oliver
Graduate Student Theses, Dissertations, & Professional Papers
We evaluate the sensitivity of Earth's elastic deformation to groundwater hydraulic diffusivity using coupled groundwater and elastic deformation models. Seasonal changes in terrestrial water storage cause deformation to the Earth’s crust and deeper interior that is within the observational capacity of GPS instruments. We couple finite difference groundwater simulations with geodetic forward models of crustal displacement to investigate the ability of geodetic deformation to constrain bedrock hydrologic properties. We use MODFLOW-2005 to simulate seasonal changes in groundwater flow and storage, and then use the LoadDef elastic deformation model to forward model surface displacement caused by the change in terrestrial water …
Nitrogen Dynamics And Transport Along Flowpaths In A Rural Wetland-Stream Complex, Colton Kyro
Nitrogen Dynamics And Transport Along Flowpaths In A Rural Wetland-Stream Complex, Colton Kyro
Graduate Student Theses, Dissertations, & Professional Papers
Human activities have doubled the rate of nitrogen inputs onto the landscape resulting in elevated nitrogen concentrations in our streams. Anthropogenically applied nitrogen is largely transported to stream networks via groundwater movement. Groundwater discharge occurs in distinct points along a stream but whose influences can often persist far beyond that area due to insufficient biogeochemical removal of imported nitrogen potentially causing alterations in community structure and precipitating large algae blooms. To understand the factors governing nitrogen abundance in a historical polluted stream, I used a mass-balance approach to quantify groundwater-surface water interaction and the magnitude of groundwater nitrogen input and …
Quantifying Bedrock Recharge In Two Paired Mountainous Watersheds, Kimberly Bolhuis
Quantifying Bedrock Recharge In Two Paired Mountainous Watersheds, Kimberly Bolhuis
Graduate Student Theses, Dissertations, & Professional Papers
This study focuses on 1) estimating the magnitude of bedrock recharge and 2) mean transit time as a function of bedrock permeability in two paired catchments underlain by different lithology. Networks of bedrock wells and stream gauges were installed in two adjacent catchments of approximately the same size in west central Montana. Fracture network properties for both lithologies were characterized from borehole core logging and scan lines on exposed outcrop. Recharge was evaluated using the Water Table Fluctuation (WTF) method on bedrock well hydrographs installed in both catchments. Stable water isotope samples, collected approximately monthly, from precipitation and stream water …
Detecting Groundwater Discharge In The Clark Fork River Near Stone Container Using Spectral Alpha Decay Detection For Dissolved Radon In Surface Water Samples Abstract, Daniel William Forsland
Detecting Groundwater Discharge In The Clark Fork River Near Stone Container Using Spectral Alpha Decay Detection For Dissolved Radon In Surface Water Samples Abstract, Daniel William Forsland
Undergraduate Theses, Professional Papers, and Capstone Artifacts
Radon-222 (222Rn) was measured along 8.7 kilometers of the Clark Fork River, between Harper’s Bridge and Frenchtown, MT. Twelve water samples were taken along the stretch. Samples 1 through 4 and 10 through 12 were collected on a 1 km interval, samples 5 through 9 were taken on a 500 meter interval. Samples were analyzed for dissolved 222Rn using a RAD7 spectral alpha decay detector. Instream 222Rn was modeled to quantify groundwater discharge to the river. Literature on the Missoula Valley aquifer was analyzed, revealing an alluvial aquifer system to the east consisting of interbedded gravel, …
Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler
Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler
Public Land & Resources Law Review
In Hawai’i Wildlife Fund v. County of Maui, the Ninth Circuit held that the plain language of the Clean Water Act provides jurisdiction over indirect discharges of pollutants from a point source into groundwater that is shown to be connected to navigable waters. The court found that studies confirmed pollutants entering the Pacific Ocean were fairly traceable to the County of Maui’s sewage disposal wells. In affirming the district court’s ruling, the Ninth Circuit held that Maui County violated the Clean Water Act by discharging pollutants into a navigable water without the required permit. The court also concluded the …
Estimating Groundwater Inflow And Age Characteristics In An Alluvial Aquifer Along The Little Wind River, Wyoming, Derek Goble
Estimating Groundwater Inflow And Age Characteristics In An Alluvial Aquifer Along The Little Wind River, Wyoming, Derek Goble
Graduate Student Theses, Dissertations, & Professional Papers
We synoptically sampled a 2 km gaining reach of the Little Wind River in central Wyoming for 222Rn, CFCs and SF6 to determine the distributed volumes and locations of discharge and estimate alluvial groundwater age characteristics. 222Rn was sampled in the stream, shallow in-stream piezometers and nearby alluvial groundwater wells to determine the volume and spatial distribution of groundwater discharge to the river. Age tracers, CFC and SF6, sampled in the stream, shallow in-stream piezometers and in alluvial groundwater wells were then used to determine whether in-stream samples are capable of constraining the residence time distribution …
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 …
Detecting Regional Groundwater Discharge To The Clark Fork River, Melinda Horne
Detecting Regional Groundwater Discharge To The Clark Fork River, Melinda Horne
Undergraduate Theses, Professional Papers, and Capstone Artifacts
In this study, Radon-222 (222Rn) measured in stream water and groundwater was used to constrain the quantity of groundwater discharge along a 22 km reach of the Clark Fork River as it runs through Missoula, MT. Dissolved 222Rn samples were taken at 2 km intervals along a reach extending from the confluence of the Clark Fork and the Blackfoot River near Bonner, MT to the confluence with the Bitterroot River on the northwestern edge of the Missoula Valley. Groundwater samples were taken from wells in an alluvial aquifer near Rattlesnake Creek, and combined with previous data from …
The Effect Of Spatial Patterns Of Soil Hydraulic Conductivity And Depth On Local And Hillslope Scale Shallow Water Table Dynamics, Casey E. Ryan
The Effect Of Spatial Patterns Of Soil Hydraulic Conductivity And Depth On Local And Hillslope Scale Shallow Water Table Dynamics, Casey E. Ryan
Graduate Student Theses, Dissertations, & Professional Papers
Much research in forested headwater catchments has focused on the role of topography for organizing subsurface flow and the hydrologic connectivity of upland flow paths to stream networks. However, little work has been conducted to evaluate how localized and hillslope scale patterns of hydraulic conductivity and soil depth contribute to spatial patterns of water table duration, magnitude, and connectivity. I monitored shallow groundwater dynamics in wells distributed across a 1st order hillslope in the Lubrecht Experimental Forest, Montana. Additionally, I collected in-situ measurements of soil saturated hydraulic conductivity and soil depth at 10m intervals across the study hillslope and compared …