Digital Commons Network^™

Monitoring Groundwater Flow At Old Works Using Anisotropy, 3-D Electrical Geophysics, And Dem-Based Terrain Analysis, Yihaun Gao

Honors Theses

Groundwater flow in shallow heterogeneous environments is often difficult to characterize using a single geophysical method. This study applies an integrated approach combining azimuthal resistivity anisotropy, self-potential (SP) measurements, DEM-derived terrain indices, and three-dimensional electrical resistivity tomography (3-D ERT) to delineate preferential groundwater pathways at the Old Works Golf Course in Anaconda, Montana. Azimuthal anisotropy analysis from eighteen 2-D ERT profiles revealed a dominant directional dependence in electrical conductivity, indicating a structural or sedimentological control on subsurface flow. The anisotropy results indicate a preferred conductivity direction of approximately 200°–210° in azimuth (0° is north), suggesting that groundwater movement is guided …

Widespread Infilling Of Tidal Channels And Navigable Waterways In The Human-Modified Tidal Deltaplain Of Southwest Bangladesh, C. Wilson, S. Goodbred, C. Small, J. Gilligan, S. Sams, B. Mallick, R. Hale

OES Faculty Publications

Since the 1960s, ~5000 km² of tidal deltaplain in southwest Bangladesh has been embanked and converted to densely inhabited, agricultural islands (i.e., polders). This landscape is juxtaposed to the adjacent Sundarbans, a pristine mangrove forest, both well connected by a dense network of tidal channels that effectively convey water and sediment throughout the region. The extensive embanking in poldered areas, however, has greatly reduced the tidal prism (i.e., volume of water) transported through local channels. We reveal that >600 km of these major waterways have infilled in recent decades, converting to land through enhanced sedimentation and the direct blocking …

Use Of Environmental Isotope Tracer And Gis Techniques To Estimate Basin Recharge, Abdulganiu A.A. Odunmbaku

Open Access Theses & Dissertations

The extensive use of ground water only began with the advances in pumping technology at the early portion of 20th Century. Groundwater provides the majority of fresh water supply for municipal, agricultural and industrial uses, primarily because of little to no treatment it requires. Estimating the volume of groundwater available in a basin is a daunting task, and no accurate measurements can be made. Usually water budgets and simulation models are primarily used to estimate the volume of water in a basin.

Precipitation, land surface cover and subsurface geology are factors that affect recharge; these factors affect percolation which invariably …

Sedimentology And Stratigraphy Of The Pennsylvanian Saginaw Aquifer, Central Lower Michigan, U.S.A., Niah B. H. Venable

Masters Theses

The Saginaw Aquifer is an important bedrock aquifer serving the needs of over 400,000 people in the Tri-County area of the Central Lower Peninsula of Michigan. The aquifer is comprised of the Pennsylvanian Grand River and Saginaw Formations. This study focuses on expanding existing knowledge of the general sedimentologic and stratigraphic characteristics of these units using conventional geological methods including core analysis, local log to core correlation, local and regional log to log correlation, and biostratigraphy. Analysis of new core from the study area examines facies and depositional environments given cursory coverage in outcrop studies by past researchers.

Incised valley …