Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Earth Sciences (6)
- Hydrology (5)
- Computer Sciences (2)
- Environmental Sciences (2)
- Water Resource Management (2)
-
- Artificial Intelligence and Robotics (1)
- Biogeochemistry (1)
- Ecology and Evolutionary Biology (1)
- Geophysics and Seismology (1)
- Glaciology (1)
- Life Sciences (1)
- Mathematics (1)
- Numerical Analysis and Scientific Computing (1)
- Other Earth Sciences (1)
- Other Mathematics (1)
- Other Physical Sciences and Mathematics (1)
- Systems Biology (1)
- Terrestrial and Aquatic Ecology (1)
Articles 1 - 8 of 8
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 …
Relating Streamflow Discharge To Surface Elastic Response Under Hydrologic Loading Using Single Gps Vertical Displacement And The Storage-Discharge Relationship At Local Watershed Scales, Noah B. Clayton
Graduate Student Theses, Dissertations, & Professional Papers
Uncertainties associated with climate change and increasing demands for water resources require better methods for estimating water availability at small to intermediate watershed scales (<1500 km2). Temporal changes in watershed storage and transport across various watersheds in the western U.S. were investigated using the hydrologic loading signal from GPS vertical displacements as a proxy for changes in watershed total terrestrial storage. GPS vertical displacement and streamflow discharge relationships were analyzed at daily to monthly temporal resolution. Stream connected storage changes were inferred using discharge using a first-order dynamical system model. Storage inferred from discharge, GPS vertical displacement and storage …
A Dual State Hierarchical Ensemble Kalman Filter Algorithm, William J. Cook, Jesse Johnson, Marko Maneta, Doug Brinkerhoff
A Dual State Hierarchical Ensemble Kalman Filter Algorithm, William J. Cook, Jesse Johnson, Marko Maneta, Doug Brinkerhoff
Graduate Student Theses, Dissertations, & Professional Papers
Dynamic models that simulate processes across large geographic locations, such as hydrologic models, are often informed by empirical parameters that are distributed across a geographical area and segmented by geological features such as watersheds. These parameters may be referred to as spatially distributed parameters. Spatially distributed parameters are frequently spatially correlated and any techniques utilized in their calibration ideally incorporate existing spatial hierarchical relationships into their structure. In this paper, a parameter estimation method based on the Dual State Ensemble Kalman Filter called the Dual State Hierarchical Ensemble Kalman Filter (DSHEnKF) is presented. This modified filter is innovative in that …
Ice Flow Impacts The Firn Structure Of Greenland's Percolation Zone, Rosemary C. Leone
Ice Flow Impacts The Firn Structure Of Greenland's Percolation Zone, Rosemary C. Leone
Graduate Student Theses, Dissertations, & Professional Papers
One dimensional simulations of firn evolution neglect horizontal transport as the firn column moves down slope during burial. This approach is justifiable near Greenland's ice divide, where ice flow is near vertical, but fidelity is lost in the percolation zone where horizontal ice flow advects the firn column through climate gradients. We simulate firn evolution processes under advection conditions using a transient, thermo-mechanically coupled model for firn densification and heat transfer with various schemes for meltwater penetration and refreezing. The simulations isolate processes in synthetic runs and investigate an ice core site and four transects of Greenland’s percolation zone. The …
An Inter-Watershed Comparison Study Of Bedrock Controls On Shallow Subsurface Flow And Streamflow Response, Robert Livesay
An Inter-Watershed Comparison Study Of Bedrock Controls On Shallow Subsurface Flow And Streamflow Response, Robert Livesay
Graduate Student Theses, Dissertations, & Professional Papers
Bedrock controls on watershed response have been actively studied in recent years, however, most conclusions are based on surface water analysis leaving unresolved questions about the nature of bedrock flow paths and ultimately their control on watershed response. In this study, we investigated bedrock controls on watershed response by simultaneously monitoring the hydrology of two adjacent watersheds underlain by dissimilar geologic formations (monzonite vs. meta-sandstone) and by characterizing subsurface conditions through bedrock drilling and fracture mapping. We hypothesized, when soils saturate, the underlying bedrock geology may influence the partitioning of shallow subsurface flow (SSF) between soil and bedrock flow paths, …
Hydraulic Conductivity As A Proxy For Drainage System Connectivity In A Subglacial Hydrology Model, Jacob Z. Downs
Hydraulic Conductivity As A Proxy For Drainage System Connectivity In A Subglacial Hydrology Model, Jacob Z. Downs
Graduate Student Theses, Dissertations, & Professional Papers
The link between subglacial hydrology and basal sliding has prompted work on basal hydrology models with water pressure and storage as prognostic variables. We find that a commonly used model of distributed drainage through linked cavities underpredicts winter water pressure when compared to borehole observations from Issunguata Sermia in Western Central Greenland. Possible causes for this discrepancy including unrealistic model inputs or unconstrained parameters are investigated through a series of modeling experiments on both synthetic and realistic ice sheet geometries. We find that conductivity acts as a proxy for the connectivity of the linked cavity system and should therefore change …
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 …