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Full-Text Articles in Physical Sciences and Mathematics

Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen Dec 2020

Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen

Dissertations

Our recent analysis of Temporal Gravity Recovery and Climate Experiment (GRACE) solutions over the largest aquifer system in Africa (the Nubian Sandstone Aquifer System: NSAS) revealed that while the response of deep aquifers to climatic variations remains a relatively slow process that takes thousands to tens of thousands of years, there is a much faster response in aquifers that are characterized by dense networks of faults, fractures and karst as is the case with the NSAS. This rapid groundwater flow, when it occurs, is detected as an increase in GRACETWS over areas downgradient and distant (hundreds of km) from …


Groundwater Withdrawal Prediction Using Integrated Multitemporal Remote Sensing Data Sets And Machine Learning, S. Majumdar, Ryan G. Smith, J. J. Butler, V. Lakshmi Nov 2020

Groundwater Withdrawal Prediction Using Integrated Multitemporal Remote Sensing Data Sets And Machine Learning, S. Majumdar, Ryan G. Smith, J. J. Butler, V. Lakshmi

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Effective monitoring of groundwater withdrawals is necessary to help mitigate the negative impacts of aquifer depletion. In this study, we develop a holistic approach that combines water balance components with a machine learning model to estimate groundwater withdrawals. We use both multitemporal satellite and modeled data from sensors that measure different components of the water balance and land use at varying spatial and temporal resolutions. These remote sensing products include evapotranspiration, precipitation, and land cover. Due to the inherent complexity of integrating these data sets and subsequently relating them to groundwater withdrawals using physical models, we apply random forests -- …


Tidal Wetland Inundation And Vegetation Phenology From Space: A Synthesis Of Approaches For Characterizing Ecological Status And Inundation Dynamics In Tidal Wetlands With Remote Sensing Observations, Brian T. Lamb Sep 2020

Tidal Wetland Inundation And Vegetation Phenology From Space: A Synthesis Of Approaches For Characterizing Ecological Status And Inundation Dynamics In Tidal Wetlands With Remote Sensing Observations, Brian T. Lamb

Dissertations, Theses, and Capstone Projects

This dissertation focuses on the monitoring and characterization of tidal marshes using remote sensing-based approaches. Chapter 1 introduces the topics of wetland ecology and remote sensing. Chapters 2-4 are the main research chapters of the dissertation covering the topics of tidal marsh mapping, tidal marsh vegetation characterization, and assessment of tidal marsh inundation patterns. Chapter 5 summarizes the preceding chapters and highlights future research directions.

The primary research objective of Chapter 2 is the mapping and study of tidal marshes of the Chesapeake and Delaware Bays. This chapter also features a thematic focus on the evaluation of various forms of …


An Integrated Approach (Remote Sensing, Hydrogeology, Gis, And Statistical Modeling) To Identify The Distribution Of Shallow Groundwater Occurrences Over Southwest Saudi Arabia, Fahad Khudier Alshehri Jun 2020

An Integrated Approach (Remote Sensing, Hydrogeology, Gis, And Statistical Modeling) To Identify The Distribution Of Shallow Groundwater Occurrences Over Southwest Saudi Arabia, Fahad Khudier Alshehri

Dissertations

Identifying shallow (near-surface) groundwater in arid and hyper-arid areas has significant societal benefits, yet it is a costly operation when traditional methods (geophysics and drilling) are applied over large domains. In this study, we developed and successfully applied methodologies that rely heavily on readily available temporal, visible and near-infrared, radar, and thermal remote sensing data sets and field data, as well as statistical approaches to map the distribution of shallow (1–5 m deep) groundwater occurrences in Al Qunfudah Province, Saudi Arabia and to identify the factors controlling their development. A four-fold approach was adopted: (1) constructing a digital database to …


Annual And Seasonal Surface Circulation Over The Mid Atlantic Bight Continental Shelf Derived From A Decade Of High Frequency Radar Observations, Hugh Roarty, Scott Glenn, Joseph Brodie, Laura Nazzaro, Michael Smith, Ethan Handel, Josh Kohut, Teresa Updyke, Larry Atkinson, William Boicourt, Wendell Brown, Harvey Seim, Mike Muglia, Haixing Wang, Donglai Gong Jan 2020

Annual And Seasonal Surface Circulation Over The Mid Atlantic Bight Continental Shelf Derived From A Decade Of High Frequency Radar Observations, Hugh Roarty, Scott Glenn, Joseph Brodie, Laura Nazzaro, Michael Smith, Ethan Handel, Josh Kohut, Teresa Updyke, Larry Atkinson, William Boicourt, Wendell Brown, Harvey Seim, Mike Muglia, Haixing Wang, Donglai Gong

CCPO Publications

A decade (2007–2016) of hourly 6‐km‐resolution maps of the surface currents across the Mid‐Atlantic Bight (MAB) generated by a regional‐scale High Frequency Radar network are used to reveal new insights into the spatial patterns of the annual and seasonal mean surface flows. Across the 10‐year time series, temporal means and interannual and intra‐annual variability are used to quantify the variability of spatial surface current patterns. The 10‐year annual mean surface flows are weaker and mostly cross‐shelf near the coast, increasing in speed and rotating to more alongshore directions near the shelfbreak, and increasing in speed and rotating to flow off‐shelf …