Physical Sciences and Mathematics Commons^™

High-Resolution Timeseries Analysis Of Dynamic Geochemistry: A 27-Well Survey Of Contaminated Groundwater Downstream Of The Former S-3 Ponds, Oak Ridge, Tennessee, Emma Dixon

Masters Theses

Spatiotemporal variability of geochemistry of contaminated groundwater has large implications on overall water quality and ability to respond to remedial applications. Gaining knowledge of how geochemistry changes over time in an area can help establish response trends to changing external conditions like weather and level of contamination. In this study, a spatiotemporal survey was performed on 27 wells at the Y-12 Complex in Oak Ridge, Tennessee. This was completed to measure diurnal fluxes in geochemistry from seasonal changes and extreme weather conditions in three areas of historically different contamination levels from a single point contamination source. Measurements were gathered over …

Hydrogeophysical Characterization And Imaging In The Mangrove Lakes Region Of Everglades National Park And Big Pine Key, Florida, Usa, Michael Eyob Kiflai

FIU Electronic Theses and Dissertations

Coastal groundwater aquifers are susceptible to saltwater intrusion from natural and anthropogenic sources. Everglades National Park (ENP) has been adversely impacted by past human activities that altered freshwater flow through the system. In Big Pine Key (BPK), the flat and low-lying topography less than 2m makes the freshwater lens vulnerable to tidal and storm surge events. This study investigated different inversion scenarios and used Electrical Resistivity Tomography (ERT) and Electromagnetic (EM) survey to characterize the spatial and temporal change of the groundwater chemistry and image the aquifers. In Big Pine Key, Hurricane Irma made landfall as a category 4 storm …

Exploring The Potential Of Nutrient Retention And Recycling With Wetlaculture Systems In Ohio With Physical And Landscape Models, Bingbing Jiang

USF Tampa Graduate Theses and Dissertations

Significant expansion of agricultural land use has been widely recognized for leading to global and regional negative environmental impacts, especially increased eutrophication of surface water systems for the last half-century. The landscape-scale environmental problem of overloading nutrients to lakes and streams by excessive fertilizer use and increased human-caused N-fixation is in urgent need of a sustainable landscape-scale solution. Wetlands have long been considered as an effective way to remove nutrients from surface water. However, the influence of regional seasonality and hydrologic conditions on agricultural runoff treatment wetlands still needs more investigation. A new approach, “wetlaculture,” has recently described as a …

Compound Flooding In Coastal Areas Emanating From Inland And Offshore Events, Hamed Behzad Koochaksaraii

Dissertations

The vulnerability of urban populations to natural hazards and climate change is a major theme in many reports on coastal cities with flooding ranking highly among the climate change concerns. Flooding could occur as a result of runoff for inland rainfall that accumulates at the mouth of the estuary to the sea or it could occur due to a storm surge emanating from the ocean. The techniques for modeling the flooding from these events are very different, as they were developed in different scientific fields: hydrology and hydraulic engineering for inland rainfall versus coastal oceanography and coastal engineering for offshore …

Year Long Water Quality Analysis Of White Horn Brook, Kevin Dyer

Senior Honors Projects

KEVIN DYER (Marine Biology)

Year-long Analysis of the Water Quality of White Horn Brook

Sponsor: Thomas Boving (Geological Sciences)

Water is the foundation for all life on earth and is the most vital resource on this planet. Despite this, oceans and waterways all over the world are being polluted and exploited in ways detrimental to their fundamental hydrologic functions. For instance, excess nitrate levels can lead to eutrophication which gives rise to harmful algae blooms. Low pH can cause the breakdown of CaCO3 exoskeletons of organisms, such mollusks. High temperature variations are major stressors to living things and can cause …

Changes In Land Use Land Cover (Lulc), Surface Water Quality And Modelling Surface Discharge In Beaver Creek Watershed, Northeast Tennessee And Southwest Virginia, Tosin James

Electronic Theses and Dissertations

Beaver Creek is an impaired streams that is not supporting its designated use for recreation due to Escherichia coli (E.coli), and sediment. To address this problem, this thesis was divided into two studies.

The first study explored changes in Land Use Land Cover (LULC), and its impact on surface water quality. Changes in E.coli load between 1997-2001 and 2014-2018 were analyzed. Also, Landsat data of 2001, and 2018 were examined in Terrset 18.31. Mann-Whitney test only showed a significant reduction in E.coli for one site. Negative correlation was established between E.coli load, and Developed LULC, Forest LULC, and …

Earth Observation And Cloud Computing In Support Of Two Sustainable Development Goals For The River Nile Watershed Countries, Wenzhao Li, Hesham El-Askary, Venkat Lakshmi, Thomas Piechota, Daniele Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

In September 2015, the members of United Nations adopted the 2030 Agenda for Sustainable Development with universal applicability of 17 Sustainable Development Goals (SDGs) and 169 targets. The SDGs are consequential for the development of the countries in the Nile watershed, which are affected by water scarcity and experiencing rapid urbanization associated with population growth. Earth Observation (EO) has become an important tool to monitor the progress and implementation of specific SDG targets through its wide accessibility and global coverage. In addition, the advancement of algorithms and tools deployed in cloud computing platforms provide an equal opportunity to use EO …

Modeling Drought, Drought Teleconnection, And Its Effect On Groundwater Level Dynamics In The Biscayne Aquifer, Anteneh Z. Abiy

FIU Electronic Theses and Dissertations

Developing a self-sufficient water supply system in Southeast Florida is one input to the success of the ongoing restoration effort in the Everglades. Maintaining a high groundwater level in the urban side of the Biscayne Aquifer (BA) is important to sustain the urban water supply. However, the long-term groundwater table condition in the Biscayne Aquifer (BA) is threatened by a combination of drought, groundwater pumping, and sea-level rise. Further, the long-term drought pattern, drought drivers, and the aquifer’s response to drought and other stress conditions are not well known. As a result, options that would help to maintain a high …

Influence Of Forest-To-Silvopasture Conversion And Drought On Components Of Evapotranspiration, Adam P. Coble, Alexandra R. Contosta, Richard G. Smith, Nathan W. Siegert, Matthew A. Vadeboncoeur, Katie A. Jennings, Anthony J. Stewart, Heidi Asbjornsen

Natural Resources & the Environment

The northeastern U.S. is projected to experience more frequent short-term (1-2 month) droughts interspersed among larger precipitation events. Agroforestry practices such as silvopasture may mitigate these impacts of climate change while maintaining economic benefits of both agricultural and forestry practices. This study evaluated the effects of forest-to-silvopasture (i.e., 50% thinning) conversion on the components of evapotranspiration (transpiration, rainfall interception, and soil evaporation) during the growing season of 2016. The study coincided with a late-summer drought throughout the northeastern U.S., which allowed us to also evaluate the effects of forest-to-silvopasture conversion on drought responses of multiple tree species, including Pinus strobus, …

A Spatially Distributed Investigation Of Stream Water Temperature In A Contemporary Mixed-Land-Use Watershed, Jason P. Horne

Graduate Theses, Dissertations, and Problem Reports

Stream water temperature is an important physical variable that influences many biological and abiotic water quality processes. The land-use/land-cover (LULC) types and corresponding variability in stream water temperature (Tw) processes in contemporary mixed-land-use watersheds necessitate research to advance management and policy decisions. Water temperature was analyzed from 21 gauging sites using a nested-scale experimental watershed study design. Results showed that forested land use was significantly negatively correlated (α = 0.05) with mean and maximum Tw. Agricultural land use was significantly positively correlated (α = 0.05) with maximum Tw except during the spring season. Mixed development and Tw were significantly correlated …

Spatial And Temporal Controls On Streamflow Variability In The San Juan Mountains, Colorado, Christopher Lewis Hancock

Electronic Theses and Dissertations

This project characterizes and examines changes to the annual hydroclimatic cycle throughout alpine regions of Colorado with a focus on trends in snowpack and snowmelt hydrology. Datasets analyzed for this research include 79 SNOTEL sites throughout Colorado (24 in the San Juan Mountains) which provide climate metrics for Water Years 1988-2018. Impacts on streamflow are evaluated in the San Juan Region through a network of 11 USGS stream gauges. Correlation matrices and linear regression methods examine the relative controls on the magnitude and timing of discharge, and trend detection using the regional Kendall test quantifies the rate of change within …

Impact Of Seismic Lines On The Hydrology Of Wetlands In The Discontinuous Permafrost Zone, Southwestern Northwest Territories, Angela Hamilton

Theses and Dissertations (Comprehensive)

Previous studies in the southern Northwest Territories have shown the underlying discontinuous permafrost is sensitive to disturbances such as the creation of seismic lines. Their creation has resulted in compaction topsoil and tree removal causing accelerated permafrost thaw. The loss of permafrost has caused seismic lines’ surface elevation to subside, which allows water to conjugate. This increases the soil moisture of a seismic line, which results in preferential thaw along the seismic line edges. Thaw along the edges over time has connected more previously isolated wetlands to seismic lines. This leads to more water entering, resulting in higher water levels …