Physical Sciences and Mathematics Commons^™

Groundwater In Nebraska, Troy E. Gilmore, Jesse T. Korus Dr.

Conservation and Survey Division

What is groundwater? Groundwater is water that fills and moves between spaces in underground rocks, gravel, sand, or other materials.

Modeling Overdraft-Driven Nitrate Transport In Shallow Wells For Mitigation And Scenario Planning, Jonathan Cronk

Department of Biological Systems Engineering: Dissertations and Theses

In Nebraska, average nitrate concentrations in groundwater have doubled since 1974, making water quality management more important than ever. As droughts, heat waves, and floods become more common climate events, understanding their impacts will be necessary to make informed management decisions. Emerging literature describes that drought correlates to an increase in the concentration of nitrate-N at domestic and irrigation wells, however the relative contributions of the mechanisms thought to be responsible is currently unknown.

This research assessed the impact of recharge and pumping rate changes as two mechanisms affecting nitrate-N concentration during drought, assessed the relationship between well depth and …

Small Community Water Systems Have The Highest Prevalence Of Mn In Drinking Water In California, Usa, Miranda Aiken, Samantha C. Ying

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Manganese (Mn) is currently regulated as a secondary contaminant in California, USA; however, recent revisions of the World Health Organization drinking water guidelines have increased regulatory attention of Mn in drinking water due to increasing reports of neurotoxic effects in infants and children. In this study, Mn concentrations reported to California’s Safe Drinking Water Information System were used to estimate the potentially exposed population within California based on system size. We estimate that between 2011 and 2021, over 525,000 users in areas with reported Mn data are potentially exposed to Mn concentrations exceeding the WHO health-based guideline (80 μg L …

Predictive Modeling Of Cave Entrance Locations: Relationships Between Surface And Subsurface Morphology, William Blitch, Adia R. Sovie, Benjamin Tobin

Faculty, Staff, and Affiliated Publications--KGS

Cave entrances directly connect the surface and subsurface geomorphology in karst landscapes. Understanding the spatial distribution of these features can help identify areas on the landscape that are critical to flow in the karst groundwater system. Sinkholes and springs are major locations of inflow and outflow from the groundwater system, respectively, however not all sinkholes and springs are equally connected to the main conduit system.

Predicting where on the landscape zones of high connectivity exist is a challenge because cave entrances are difficult to detect and imperfectly documented. Wildlife research has a similar issue of understanding the complexities of where …

Importance Of Snowmelt On Soil Nitrate Leaching To Groundwater – A Model Study, Sahila Beegum, Arindam Malakar, Chittaranjan Ray, Daniel D. Snow

Nebraska Water Center: Faculty Publications

The movement of nitrate to surface water bodies during snow accumulation and melting has been extensively studied, but there are only limited studies on the influence of snow processes on nitrate leaching to groundwater. The present study investigated the impact of snow processes on nitrate leaching to groundwater based on a simulation modeling approach using HYDRUS-1D. HYDRUS-1D model has a temperature threshold-based snow model in addition to water, solute, and heat simulation components. The snow component in HYDRUS-1D was previously not applied to snow simulation studies since the method does not consider a detailed physical and process-based representation of snow …

Effects Of Salix Psammophila On Groundwater Recharge In A Semiarid Area Of North China, Lizhu Hou, Jingdong Gao, Bill X. Hu, Xixi Wang

Civil & Environmental Engineering Faculty Publications

Study region: The semiarid Mu Us Sandy Land (MUSL) was selected for this study. It is in the farming-pastoral ecotone of north China and functions as an eco-environmental barrier.

Study focus: Afforestation can mitigate desertification and soil erosion by improving hydrologic condition, which is particularly true for semiarid and arid regions. However, little is known about the quantitative response of hydrologic improvement to afforestation level that can be measured by leaf area index (LAI). The objective was to setup and use a physically-based model to quantitatively assess the dynamics of water fluxes from Salix psammophila afforestation in the MUSL.

New …

Carbon Cycling And Critical Zone Dynamics In An Urbanized Karst Groundwater System, Amy Hourigan

Masters Theses & Specialist Projects

Increasing atmospheric CO₂ concentrations are correlated to rising global temperatures. Investigating the cumulative global carbon cycling processes is important to understand and quantify the global carbon cycle. By investigating basic geochemical parameters, EpCO₂, DIC, and δ¹³C_DIC, at four sites along Lost River Cave (LRC), in Bowling Green, Kentucky, concentrations, fluxes and sources of C dissolved in groundwater were determined. Urban karst groundwater systems, compared to more natural karst landscapes, typically exhibit widespread impervious, heat-absorbing surfaces, urban heat island effects, and increased anthropogenic groundwater inputs and localized CO₂ emissions. Carbonate hydrogeochemical …

Identifying The Isotopic Signature Of Lake-Effect Precipitation In Shallow Groundwater, Andrew Brown

Honors Projects

Three different stable isotopes of water occur in nature, with the majority of water on Earth containing the oxygen isotope 16O. These isotopes have slightly differing physical and chemical properties. H2O with heavier oxygen isotopes should theoretically precipitate earlier than lighter isotope H2O, meaning this natural process should allow for the observation of the magnitude of effects of lake-effect precipitation on the basis of water isotope differences. Furthermore, it may allow for better understanding of the significance lake-effect precipitation plays in recharging shallow aquifers. In this study, patterns of lake-effect precipitation from Lake Michigan were observed in a collection of …

Groundwater Modeling Of The West Plains, Wa, Erin L. Toulou, Chad Pritchard Phd, Lauren Stachowiak Phd

2022 Symposium

Located in Eastern Washington in the West Plains Region sits a plateau of Columbia River Basalts between Deep Creek, Hangman Creek, and south of the Spokane River. Primarily in Airway Heights, the amount of drinking water as well as the quality of the water has affected residents in the area. The most recent issue is PFAS contamination, which is thought to negatively affect human health and is found in drinking water wells across the West Plains. We can interpret subsurface geology using new well logs from Fairchild Air Force Base and in the Palisades area. When using ArcGIS PRO, well …

Arsenic In Groundwater Sources From Selected Communities Surrounding Taal Volcano, Philippines: An Exploratory Study, Geminn Louis C. Apostol, Sary Valenzuela, Xerxes Seposo

Ateneo School of Medicine and Public Health Publications

Arsenic (As) is a highly toxic, carcinogenic trace metal that can potentially contaminate groundwater sources in volcanic regions. This study provides the first comparative documentation of As concentrations in groundwater in a volcano-sedimentary region in the Philippines. Matched, repeated As measurements and physico-chemical analyses were performed in 26 individual wells from 11 municipalities and city in Batangas province from July 2020 to November 2021. Using the electrothermal atomic absorption spectrometric method, analysis of the wells revealed that in 2020, 23 out of 26 (88.46%) had As levels above the WHO limit of >10 ppb while 20 out of 26 wells …

Baseflow And Water Resilience Variability In Two Water Management Units In Southeastern Brazil, Lucas Vituri Santarosa, Didier Gastmans, Troy E. Gilmore, Jan Boll, Sebastian Balbin Betancur, Vitor Fidelis Monteiro Gonçalves

Conservation and Survey Division

Changes in climate and water demand in densely populated regions increasingly affect hydrological systems, and, in turn, impact socioeconomic conditions. In this case study, we identify how the hydrogeological frameworks of two water resource management units, Tietê-Jacaré (TJ) and Piracicaba-Capivari-Jundiaí (PCJ) in Sao Paulo state (Brazil), control the baseflow processes and resilience in the face of streamflow fluctuations in response to anthropogenic activities and climate variation. The results reveal between 40% and 75% contributions of baseflow to total streamflow in basins overlying crystalline and sedimentary aquifers. The basins in PCJ which mostly overly crystalline aquifers, have shorter water residence times …

Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan

Nebraska Water Center: Faculty Publications

The present research reports the level of nitrate (NO₃^-), associated health risks and possible sources of contamination in groundwater from south India. Many samples (32%) are above or approaching the recommended level of NO₃^- for safe drinking water. The correlation analysis indicates different sources of NO₃^- contamination in different regions rather than a common origin. The isotopic measurements provide information about potential nitrogen sources contributing NO₃^- to the groundwater. Based on isotope analysis, the sources of NO₃^- in the groundwater of this region are likely to be from (a) …

Integrating Compound Flood Conditions Through 2d Hydraulic Modeling For Simulating Flood Risk Processes In Coastal Cities, Francisco Pena Guerra Mr.

FIU Electronic Theses and Dissertations

Low elevation coastal karst environments are highly vulnerable to flooding conditions due to climate change. Trends in rising global temperatures have increased the frequency and intensity of extreme precipitation, hydrometeorological phenomena and sea level rise, exacerbating the impact of pluvial, fluvial, coastal and groundwater flood hazards. Compound flooding events amplify flood hazards and pose a higher threat to residents and infrastructure in unison compared to independent phenomena. Recent advancements in coupling hydrologic and hydraulic modeling frameworks have improved our ability to account for the combined effects of extreme pluvial, fluvial, and coastal flood hazards. This innovation in the hydroinformatics field …

Statistical Analysis Of Groundwater Level Fluctuation Of The Urban And Peri-Urban Area Of Gazipur District, Bangladesh, Nowshin Ahsan Priyanka, Atika Rahman Akji, Anwar Zahid, Muhammad Qumrul Hassan, Jowaher Raza, Nazrul I. Khandaker

Publications and Research

Groundwater is the primary source for drinking, municipal, irrigation, and industrial water supply in Bangladesh. Due to unplanned urbanization and rapidly growing industries, the degradation situation has become perilous over time. Dhaka and its peri-urban regions are having drastic changes in groundwater (GW) levels. This work reviewed GW level fluctuation in the peri-urban area, which is now severely experiencing the detrimental impact of rapid urbanization and industrialization. Detail statistical investigation and Landsat image interpretation of the study area was conducted. Analysis and prediction of water level trends were conducted using variations of Mann Kendell tests. Gazipur Sadar (an upazila or …

The Importance Of Monitoring To Assess The Impact Of Climate Change On Groundwater Resources In Bangladesh, Muhammad Qumrul Hassan, Anwar Zahid, Nazrul I. Khandaker

Publications and Research

Groundwater is the major source of fresh water across much of the world, but there has been very little study on the impacts of climate change on this precious and finite resource. Rising levels of greenhouse gases are likely to increase the global average surface temperature over the next 100 years, raise sea levels and reduce soil moisture. The amount of water stored in the soil is fundamentally important to agriculture and influences the rate of actual evaporation, groundwater recharge and runoff. Rising sea levels would cause the tidal saltwater wedge to intrude further upstream in rivers, with resulting changes …

An Adaptive Hazard Planning And Mitigation Framework For Responding To Urban Contamination In Karst Aquifer Systems, James Edward Troxell

Masters Theses & Specialist Projects

Environmental hazards in karst regions are damaging and often go unnoticed until an issue has escalated to a point of affecting life or property. The field of emergency and environmental contamination response lacks planning or preparedness focused on remediating groundwater contamination in karst systems. A lack of preplanning before an incident can lead to confusion, delayed response, and the inability to remediate the contaminant. Due to the rapid movement of contaminants through urban karst groundwater aquifers, an efficient response plan that leverages localized data in a GIS should be developed and maintained in order to adequately respond. The objective of …

Desktop Review Of Groundwater Prospectivity For Irrigation In The Lower De Grey River Area, Don L. Bennett, John A. Simons

Resource management technical reports

The Department of Primary Industries and Regional Development (DPIRD) has identified priority areas in the Pilbara that warrant further investigation into their capacity for irrigated agriculture and related businesses. The De Grey River area is one of these.

The lower De Grey River area, upstream of the De Grey River Water Reserve, was identified by the Transforming Agriculture in the Pilbara (TAP) project for staged investigations of viability. Progression through these stages, each with increasingly detailed groundwater and soil suitability investigations, is dependent on prospectivity.

This document provides a summary of DPIRD’s initial desktop groundwater evaluation in the lower De …

Nebraska Statewide Groundwater-Level Monitoring Report 2020, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division

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.

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 …

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 …

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 …

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 …

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 …

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, …

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 …

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

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 …

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 …

Seasonal And Spatial Variation In The Location And Reactivity Of A Nitrate‐Contaminated Groundwater Discharge Zone In A Lakebed, Rl Smith, Da Repert, Dl Stoliker, Db Kent, Bk Song, Et Al

VIMS Articles

Groundwater discharge delivering anthropogenic N from surrounding watersheds can impact lake nutrient budgets. However, upgradient groundwater processes and changing dynamics in N biogeochemistry at the groundwater‐lake interface are complex. In this study, seasonal water‐level variations in a groundwater flow‐through lake altered discharge patterns of a wastewater‐derived groundwater contaminant plume, thereby affecting biogeochemical processes controlling N transport. Pore water collected 15 cm under the lakebed along transects perpendicular to shore varied from oxic to anoxic with increasing nitrate concentrations (10–75 μM) and corresponding gradients in nitrite and nitrous oxide. Pore water depth profiles of nitrate concentrations and stable isotopic compositions largely …

Modeling Land Subsidence Using Insar And Airborne Electromagnetic Data, Ryan G. Smith, R. Knight

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Land subsidence as a result of groundwater overpumping in the San Joaquin Valley, California, is associated with the loss of groundwater storage and aquifer contamination. Although the physical processes governing land subsidence are well understood, building predictive models of subsidence is challenging because so much subsurface information is required to do so accurately. For the first time, we integrate airborne electromagnetic data, representing the subsurface, with subsidence data, mapped by interferometric synthetic aperture radar (InSAR), to model deformation. By combining both data sets, we are able to solve for hydrologic and geophysical properties of the subsurface to effectively model the …

Using Watershed Pour-Point Elevations To Evaluate The Base Of Fresh Groundwater In The Cumberland Plateau Of Eastern Kentucky, Ethan S. L. Davis, Thomas M. Parris, Jerrad Grider

Report of Investigations--KGS

Horizontal drilling with hydraulic fracturing at shallow depths (less than 2,200 ft) in the Devonian Berea Sandstone oil and gas play, along with the potential for high-volume hydraulic fracturing in the nascent Cambrian Rogersville Shale gas play, have generated a renewed interest in protecting groundwater quality in eastern Kentucky. A critical component of protection is an accurate understanding of the distribution of fresh water in the subsurface. The “Fresh-Saline Water Interface Map of Kentucky” by H.T. Hopkins, published by the U.S. Geological Survey and Kentucky Geological Survey in 1966, has been a critical reference for assessing the maximum depth of …