Earth Sciences Commons^™

Baseflow Nitrate Dynamics Within Nested Watersheds Of An Agricultural Stream In Nebraska, Usa, Galen Richards, Troy E. Gilmore, Aaron R. Mittelstet, Tiffany Messer, Daniel D. Snow

Daugherty Water for Food Global Institute: Faculty Publications

There is a need to evaluate high surface nitrate concentrations across agricultural watersheds, both spatially and temporally, to increase understanding of source and timing of nitrogen loads in streams and rivers. Bazile Creek is a high-nitrate stream originating in the agriculturally intensive Bazile Groundwater Management Area of Eastern Nebraska, USA. It is a gaining stream that receives groundwater with high nitrate concentrations originating from nonpoint sources. The objective of this study was to determine spatial and temporal variability of baseflow nitrate concentrations in Bazile Creek and its tributaries and to relate this variability to watershed characteristics. Surface-water nitrate samples were …

Climate Change Impacts Go Beyond The Surface: Groundwater Recharge Rates And Aquifer Resources Across The Contiguous United States, Kendra R. Devereux

Senior Independent Study Theses

Groundwater is a primary source of potable water for millions and a major source for crop irrigation in the United States. Thus, it is vital to understand current and future rates of recharge to predict and manage groundwater availability. In this study, current groundwater recharge rates across the Contiguous US at 800m resolution are estimated by following methods presented by Reitz et al. (2017), and the reproducibility of the methods are assessed. A water budget approach is implemented where quick flow runoff and evapotranspiration rates are subtracted from precipitation rates. Precipitation was found to be the most reproducible water budget …

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

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 …

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 GRACE_TWS over areas downgradient and distant (hundreds of km) from …

Gradient Analysis Of Saline Groundwater Dynamics Along Spatial Transects In The Chaco, Albrecht F. Glatzle, L. Reimer, G. Roth, J. Cobo Nuñez

IGC Proceedings (1977-2023)

No abstract provided.

Relationship Between Ndvi And Hydromet Factors In Grassland Area Of Open-Pit Coal Mine, Zhang Yan, Huang Xuanming, Chen Shi, Shi Bingxing

Coal Geology & Exploration

The groundwater level of an open-pit coal mine in the grassland area of the east Inner Mongolia has been decreasing continuously under the condition of long-term drainage. In order to study whether the growth of vegetation around the mining area was affected by the decline of groundwater level, the NDVI method was used to analyze the change trend of vegetation index in the study area from 2013 to 2019. Based on the joint entropy theory, the mutual information between NDVI and different meteorological and hydrological elements(temperature, rainfall and groundwater depth)were calculated, and the main influencing factors of vegetation growth were …

A Groundwater Model Of The San Luis Obispo Valley Basin Using Comsol Multiphysics, Brian Whetsler

Master of Science in Environmental Sciences and Management Projects

A groundwater model of a subsection of the San Luis Obispo Valley basin was pro- duced using COMSOL Multiphysics 5.5 software. The goal of this project was to create a general model using forward modeling techniques which would serve as the foundation for a more refined, complete, and calibrated groundwater hydrology model. The San Luis Obispo and Edna Valley basins are characterized as high-priority by the California Sustainable Groundwater Management Act because of historic overdrafting of groundwater reserves during periods of drought in the early 1990's. Natural resource managers must use tools such as computer models to help forecast trends …

Nitrate Dynamics And Source Within Nested Watersheds Of An Agricultural Stream, Nebraska, Usa, Galen Richards

School of Natural Resources: Dissertations, Theses, and Student Research

Nitrate concentrations have been increasing throughout the globe, primarily due to heightened agricultural activity. Nitrate concentrations in Bazile Creek, located in Northeastern Nebraska, have been steadily rising since the early 2000s. Groundwater nitrate concentrations within the Bazile Creek watershed are high (> 10 mg/L nitrate-N), and there is strong connectivity between groundwater and surface water systems. This study aimed to better understand temporal nitrate concentration variability within the watershed through sampling tributaries and the main channel during baseflow conditions. Nitrate source was also investigated though the use of dual δ¹⁵N and δ¹⁸O nitrate isotopes, with samples …

Use Of Citizen Science In Monitoring Groundwater Quality: A Case Study From Nebraska, Christopher Olson

School of Natural Resources: Dissertations, Theses, and Student Research

Citizen science has a key role in modernizing effective communication between professional scientists and the general public. However, citizen science differs to that of professional science due to equipment and experience and is a topic argued against citizen science. However, technology in water quality testing has developed in simplicity and affordability to a point where high school students, with hands-on training, can collect groundwater samples and test for quality themselves. Nebraska groundwater quality is a critical part of the state and can utilize high school students as citizen scientists for their communities. High school students from rural communities across Nebraska …

A Geochemical And Statistical Investigation Of The Big Four Springs Region In Southern Missouri, Jordan Jasso Vega

Graduate Theses/Dissertations

The Big Four Springs region hosts four major first-order magnitude springs in southern Missouri and northern Arkansas. These springs are Big Spring (Carter County, MO), Greer Spring (Oregon County, MO), Mammoth Spring (Fulton County, AR), and Hodgson Mill Spring (Ozark County, MO). Based on historic dye traces and hydrogeological investigations, these springs drain an area of approximately 1500 square miles and collectively discharge an average of 780 million gallons of water per day. The rocks from youngest to oldest that are found in Big Four Springs region are the Cotter and Jefferson City Dolomite (Ordovician), Roubidoux Formation (Ordovician), Gasconade Dolomite …

Evaluation Of Groundwater Sodium And Sodium Uptake In Taxodium And Its Hybrids On Galveston Island, Texas, Daniel Morgan

Electronic Theses and Dissertations

In September 2008, Hurricane Ike swept through the Gulf of Mexico striking the Gulf Coast, claiming hundreds of lives and causing billions of dollars in damage. The hurricane left behind elevated sea salt concentrations in the soil and groundwater, preventing the unaided return of live oaks and other species to the island. To determine effective ways to ameliorate the elevated Na⁺ concentrations in the soil, eight treatments were applied to the soil and combinations of three species of plants, live oak (Quercus virginiana), hybrid bald cypress (Taxodium ‘T406’), and yellow hibiscus (Hibiscus hamabo …

Hydrogeochemical Characterization And Speleogenesis Of Sistema Huautla In Oaxaca, Mexico, Fernando Hernandez

Masters Theses & Specialist Projects

Sierra Mazateca, Mexico is home to Sistema Huautla, the deepest cave in the Western hemisphere with 1,560 meters of depth and 90 kilometers of passage, including 26 entrances distributed in a high-relief, karstified terrain, within the Sistema Huautla Karst Groundwater Basin. Exploration of the cave has generated research questions about its evolution and geomorphology given the different vadose and phreatic zones impacted by tectonic and incision processes. Dye traces during this study of Cueva de La Peña Colorada confirmed it is a fossil resurgence of the cave system. An additional cave, Cueva Elysium, was connected hydrologically in 2019, expanding the …

Groundwater Storage Loss Associated With Land Subsidence In Western United States Mapped Using Machine Learning, Ryan G. Smith, Sayantan Majumdar

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Land subsidence caused by groundwater extraction has numerous negative consequences, such as loss of groundwater storage and damage to infrastructure. Understanding the magnitude, timing, and locations of land subsidence, as well as the mechanisms driving it, is crucial to implementing mitigation strategies, yet the complex, nonlinear processes causing subsidence are difficult to quantify. Physical models relating groundwater flux to aquifer compaction exist but require substantial hydrological data sets and are time consuming to calibrate. Land deformation can be measured using interferometric synthetic aperture radar (InSAR) and GPS, but the former is computationally expensive to estimate at scale and is subject …

Climate Change Impacts The Subsurface Transport Of Atrazine And Estrone Originating From Agricultural Production Activities, Renys Enrique Barrios, Simin Akbariyeh, Chuyang Liu, Khalid Muzamil Gani, Margarita T. Kovalchuk, Xu Li, Yusong Li, Daniel D. Snow, Zhenghong Tang, John Gates, Shannon L. Bartelt-Hunt

Nebraska Water Center: Faculty Publications

Climate change will impact soil properties such as soil moisture, organic carbon and temperature and changes in these properties will influence the sorption, biodegradation and leaching of trace organic contaminants to groundwater. In this study, we conducted a modeling case study to evaluate atrazine and estrone transport in the subsurface under current and future climate conditions at a field site in central Nebraska. According to the modeling results, in the future, enhanced evapotranspiration and increased average air temperature may cause drier soil conditions, which consequently reduces the biodegradation of atrazine and estrone in the water phase. On the other hand, …

Estimating Evapotranspiration Of A Riparian Forest Using Sap Flow Measurements, James R. Solum

Master's Theses

To close the water use budget of irrigated agricultural fields in floodplains with substantial riparian corridors, it is necessary to understand groundwater usage by dominant phreatophytic vegetation, particularly when the primary source of water for irrigation comes from groundwater abstraction. We report here results of estimated evapotranspiration (ET) of a riparian forest, which were based on measurements of sap flow in phreatophytic vegetation within a riparian corridor. The riparian corridor was within a study area 75 to 140 meters wide in the lower portion of the Scotts Creek watershed, which is bounded to the west by the Pacific Ocean in …

An Analysis Of Groundwater Quality As Sampling Networks Age: The Gaps In Groundwater Monitoring, Angela Leone

Undergraduate Distinction Papers

Groundwater management is an important facet of protecting this important resource. One way that we ensure proper groundwater management is through the regular, long-term monitoring of groundwater wells at waste management sites throughout the country. This study investigates potential changes to groundwater quality attributed to degradation of well construction materials rather than impacts to aquifers from wastes. This assessment was completed using a data analysis of groundwater trends at closed landfill sites. An analysis of fifty-five sites was completed and three sites met our criteria for suitable data history. Due to the lack of suitable data, a more thorough investigation …

An Evaluation Of Bank Storage At Lake Mead Reservoir In The Southwest United States, Jon Woodrow Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A water balance model is employed at Lake Mead to monitor and verify changing hydrology that affects total volume at the reservoir. Bank storage, which is defined as the volume of water captured in permeable lithologic layers subject to changes induced by contact and proximity to an open waterbody, is one component that is updated regularly and is based upon data and methods that were developed in the 1960’s from observations made within the first 30 years of the reservoir's maturation. Since this period, the reservoir has undergone further development and a current understanding of additional hydrologic affects to bank …

Modeling The Contribution Of Poroelastic Deformation To Postseismic Geodetic Signals, Kimberly Mccormack, Marc A. Hesse, Timothy H. Dixon, Rocco Malservisi

School of Geosciences Faculty and Staff Publications

To constrain the poroelastic component of postseismic deformation, we model the subsurface hydrologic response to the Mw 7.6 subduction zone earthquake that occurred on the plate interface beneath the Nicoya peninsula in Costa Rica on 5 September 2012. The model shows that poroelastic relaxation occurs on multiple time scales and the associated deformation can be up to 2 cm for the trench‐perpendicular component. By modeling the time‐dependent deformation associated with poroelastic relaxation, we can begin to remove its contribution from the observed geodetic signal. Inversions for after slip that ignore poroelastic deformation have errors of 10–20% overall and up …

Field And Numerical Evaluation Of Nitrogen Transport From Septic Systems In Surfical Aquifer Systems To Charlotte Harbor, Florida, Tanten T. Buszka

Masters Theses

Shallow water tables in coastal surficial aquifers limit effective treatment of septic effluent which can result in excess nutrient loading into nearby surface water bodies. Approximately 45,000 septic systems in Charlotte County, Florida transmit effluent into an under studied surficial aquifer and contribute to harmful algal blooms and outbreaks of E. coli. An undeveloped field site was characterized using standard hydrogeologic methods, including a one-year duration natural gradient tracer test, to obtain representative lithology of the sandy surficial aquifer and estimates of groundwater velocity, flow directions, effective porosity and dispersion. These data were used to support the development of a …

Nebraska Statewide Groundwater-Level Monitoring Report 2019, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the total volume of the High Plains Aquifer lies beneath the State. Groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Nebraska’s total groundwater resource is vast, yet it is also vulnerable to natural and anthropogenic changes, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting form the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.

The personnel of the Conservation and Survey Division (CSD) are proud …

Declining Water Resources And Environmental Degradation: A Case Of The Thulokhola Watershed In The Nuwakot District Of Nepal, Durga D. Poudel, Timothy W. Duex

IGC Proceedings (1977-2023)

Climate change alters the hydrology of a watershed through changes on precipitation patterns, extreme rain events, increase on temperatures, degradation of forest and soil resources and drought conditions. Drought conditions create stress on agricultural crops, forests, drinking water supply for human and wildlife as well as water supply for industrial uses. Flooding destroys crops, infrastructures, private properties, and results in loss of life. Climate change impacts both the availability as well as the quality of water resources as extreme rain events tend to alter water infrastructures and pollute water sources.

In Nepal, climate change impacts include degradation of resource and …

Under Pressure: Hydraulic Fracturing, Suzanne Miller

Augsburg Honors Review

Modern hydraulic fracturing, or "fracking," is a relatively new technique that has unlocked previously unviable sources of natural gas. It involves the rapid injection of large volumes of fluids into shale formations thousands of feet below the surface to force open fractures, creating pathways for the gas to flow into the well. The recent escalation in fracking operations has already made shale formations a major source of natural gas, but the fracking process could potentially lead to groundwater contamination. This paper explores concerns over the toxic narure of fracking chemicals, the leakage of produced water and natural gas into aquifers, …

Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray

Daugherty Water for Food Global Institute: Faculty Publications

This study combines empirical predictive and economics models to estimate the cost of remediation for domestic wells exceeding suggested treatment thresholds for nitrates. A multiple logistic regression model predicted the probability of well contamination by nitrate, and a life cycle costing methodology was used to estimate costs of nitrate contamination in groundwater in two areas of Nebraska. In south-central Nebraska, 37% of wells were estimated to be at risk of exceeding a threshold of 7.5 mg/L as N, and 17% were at risk of exceeding 10 mg/L as N, the legal limit for human consumption in the United States. In …

Tidal-Groundwater Study Of The Slaughter Beach Salt Marsh In Slaughter Beach, De, Michael Powers

West Chester University Master’s Theses

Seasonal and decadal monitoring of salt marsh at Slaughter Beach, DE documented long-term and short-term variations in number and sizes of salt ponds. Over 400 salt ponds ranging in size between 0.5 m² to 0.11 km² were identified on 5.5 km² salt marsh platform. The purpose of this study is to quantify hydrologic conditions and measure groundwater discharge of a salt marsh, particularly the impact of tidal forces on groundwater fluctuation.

Four wells with nests of mini-piezometers with ONSET Pressure Transducers were installed along a transect crossing the largest salt pond (0.11 km²) in the …

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, …

A Geochemical Assessment Of Potential Groundwater Storage Locations Within The Yakima River Basin, Silas Sleeper

All Master's Theses

Currently in the Yakima River Basin more people possess surface water rights than there is available surface water. As a result, the local community devised the Yakima River Basin Integrated Water Management Plan, with the goal of creating a sustainable source of water for the foreseeable future. One of seven elements outlined in this plan is groundwater storage. The idea is to take available water during high spring flows and store it in the subsurface. The water will then be used to increase stream flows and decrease stream water temperatures during the summer months. A main challenge associated with groundwater …

The Spatial Distribution Of Elevated Uranium In The Treasure Valley Aquifer System, Southwest Idaho, Lloyd A. Womeldorph

Boise State University Theses and Dissertations

The Treasure Valley Aquifer System (TVAS) in southwestern Idaho contains well-documented uranium concentrations over the U.S. Environmental Protection Agency maximum contaminant level of 30 µg/L. With a population in the Treasure Valley projected to reach 1.6 million by 2065, in-depth horizontal and vertical spatial knowledge of the contaminant is needed. This study evaluates the horizontal and vertical spatial nature of uranium in the TVAS and interprets those observations to provide both a conceptual model of uranium behavior, and recommendations for water resource management. A large water quality dataset was compiled, and supplemented by data collected during a field sampling campaign, …

Spatial Distribution And Formation Of Groundwater Hydrochemistry In Huainan Coalfield, Wang Zitao, Liu Qimeng, Liu Yu

Coal Geology & Exploration

In order to study the spatial distribution of groundwater in Huainan coalfield and the intensity of various hydrochemical actions, the coalfied is divided into the northern district with thicker loose beds and the southern district with thinner loose beds. Hydrochemical test data of main water-inrushing aquifers in 16 mines in these two areas were collected and statistically analyzed, ion combination method and Gibbs diagram were used to study the groundwater hydrochemical characteristics of each aquifer in north and south areas. The results indicate that TDS of aquifer is positively correlated with the burial thickness of unconsolidated formation. With the increase …

Investigation Of Subsurface Stratigraphy And Groundwater Dynamics In The Mississippi River Delta, An Li

LSU Doctoral Dissertations

The Mississippi River Delta (MRD) is socioeconomically important to the state of Louisiana and the United States. Various types of land-water system data have been collected in the MRD. However, very few efforts have been made to utilize these datasets in modeling regional stratigraphy and groundwater dynamics in the MRD, especially for the upper 50 m of the depth. In this interval of depth, the Mississippi River and surrounding interdistributary bays intensively interact with the groundwater system. The lack of knowledge in regional stratigraphy and groundwater dynamics hinder an understanding of how hydrogeological setting affects processes such as surface-groundwater interaction, …