Earth Sciences Commons^™

Projected Long-Term Climate Trends Reveal The Critical Role Of Vapor Pressure Deficit For Soybean Yields In The Us Midwest, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy

Nebraska Water Center: Faculty Publications

Extreme climate events including heat waves and droughts are projected to become more frequent under future climate change conditions. However, the mechanisms between soybean yields and climate factors, specifically involving variable rainfall and high heat episodes, are still unclear, particularly with respect to spatial trends in the United States (US) Midwest. A recently modified version of the model GLYCIM was used to evaluate rainfed soybean production across 12 states at a 10 km spatial resolution for three time periods (2011–2020, 2051–2060, 2091–2099) under Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5. Results showed that except for the northernmost Midwest counties, …

Land Use/Land Cover Uncertainty Analysis Using Hydrological Modeling In The Northern Watershed Of Lake Okeechobee, Andres Lora Santos

USF Tampa Graduate Theses and Dissertations

Over the past 150 years, Florida has undergone a major land-form transformation, transitioning from a natural to a primarily built environment. The state's population has grown exponentially, from less than 50,000 residents in the 1850s to approximately 22 million residents today. This population growth has led to significant changes in land use, including urbanization, mining, and agriculture. This trend is expected to continue, with projections indicating an increase in urbanization across the state. 2070 land use/land cover projections were used as input for the Watershed Assessment Model (WAM) to analyze the potential impact of these changes on flow, total nitrogen …

Pan-Arctic Soil Moisture Control On Tundra Carbon Sequestration And Plant Productivity, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Beniamino Gioli, Barbara Bailey, George Burba, Eugénie S. Euskirchen, Jennifer D. Watts, Kyle A. Arndt, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Albertus J. Dolman, Roisin Commane, Charles E. Miller, Josh Hashemi, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Elyn R. Humphreys, Oliver Sonnentag, Gesa Meyer, Gabriel H. Gosselin, Philip Marsh, Walter C. Oechel

Daugherty Water for Food Global Institute: Faculty Publications

Long-term atmospheric CO₂ concentration records have suggested a reduction in the positive effect of warming on high-latitude carbon uptake since the 1990s. A variety of mechanisms have been proposed to explain the reduced net carbon sink of northern ecosystems with increased air temperature, including water stress on vegetation and increased respiration over recent decades. However, the lack of consistent long-term carbon flux and in situ soil moisture data has severely limited our ability to identify the mechanisms responsible for the recent reduced carbon sink strength. In this study, we used a record of nearly 100 site-years of eddy covariance …

Flood Hydrology In Tropical Coastal Catchments: Linking Watershed Dynamics To Mangrove Sedimentation, Shannon L. Jones

Electronic Theses and Dissertations

Coastal flooding is expected to be more frequent and severe from amplified flooding from sea level rise (SLR) and upstream anthropogenic activity, particularly in tropical regions. Improved hydrologic modeling and characterization are needed to better understand, predict, and manage flooding where these amplifications are expected. Yet tropical catchments are often ungauged or have limited hydrogeomorphic data. Thus, locally calibrated models that incorporate local knowledge and alternative data can be used to provide greater information. This doctoral dissertation quantifies relationships between land use, precipitation, discharge, and downstream sediment accretion in a representative ungauged catchment using a locally calibrated rainfallrunoff model validated …

Simulation Of Monthly Mean And Monthly Base Flow Of Streamflow Using Random Forests For The Mississippi River Alluvial Plain, 1901 To 2018, Benjamin J. Dietsch, William H. Asquith, Brian K. Breaker, Stephen M. Westenbroek, Wade H. Kress

United States Geological Survey: Water Reports and Publications

Improved simulations of streamflow and base flow for selected sites within and adjacent to the Mississippi River Alluvial Plain area are important for modeling groundwater flow because surface-water flows have a substantial effect on groundwater levels. One method for simulating streamflow and base flow, random forest (RF) models, was developed from the data at gaged sites and, in turn, was used to make monthly mean streamflow and base-flow predictions at 162 ungaged sites in the study area. Daily streamflow observations and computed base flow from 247 streamgages were used as the basis for the development of these RF models. RF …

Nebraska Statewide Groundwater-Level Monitoring Report 2022, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Jeffrey Westrop

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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 …

Evaluation Of Woodchip Bioditch Reactors As A Nutrient Reduction Conservation Strategy, Geoffrey K. Payne

Student Theses and Dissertations

Continued increases in nitrogen and phosphorus loads in waterways cause problems with water quality, impacting human health, the economy, and the environment. To reach nutrient load reduction targets, innovative conservation strategies should be evaluated. This study aimed to assess (1) the potential of using woodchip bioditch reactors for the mitigation of nitrate (NO3-) and soluble reactive phosphorus (SRP) in agricultural waterways; (2) the influence of orientation of the bioditch reactor to flow direction on NO3- and SRP concentrations and loads; and (3) the impact that differing wet/dry cycles have on NO3- and SRP concentrations and loads when bioditch reactors are …

Time Domain Reflectometry Waveform Interpretation With Convolutional Neural Networks, Zhuangji Wang, Shan Hua, Dennis Timlin, Yuki Kojima, Songtao Lu, Wenguang Sun, David Fleisher, Robert Horton, Vangimalla R. Reddy, Katherine Tully

Nebraska Water Center: Faculty Publications

Interpreting time domain reflectometry (TDR) waveforms obtained in soils with non-uniform water content is an open question. We design a new TDR waveform interpretation model based on convolutional neural networks (CNNs) that can reveal the spatial variations of soil relative permittivity and water content along a TDR sensor. The proposed model, namely TDR-CNN, is constructed with three modules. First, the geometrical features of the TDR waveforms are extracted with a simplified version of VGG16 network. Second, the reflection positions in a TDR waveform are traced using a 1D version of the region proposal network. Finally, the soil relative permittivity values …

Globally Scalable Approach To Estimate Net Ecosystem Exchange Based On Remote Sensing, Meteorological Data, And Direct Measurements Of Eddy Covariance Sites, Ruslan Zhuravlev, Andrey Dara, André Luís Diniz Dos Santos, Oleg Demidov, George Burba

Daugherty Water for Food Global Institute: Faculty Publications

Despite a rapid development of Nature-Based Solutions (NBS) for carbon removal in recent years, the methods for evaluating NBS still have certain gaps. We propose an approach based on a combination of remote sensing data and meteorological variables to reconstruct the spatiotemporal variation of net ecosystem exchange from eddy-covariance stations. A Lagrangian particle dispersion model was used for upscaling satellite images and flux towers. We trained data-driven models based on kernel methods separately for each selected land-cover class. The results suggest that the proposed approach to quantifying carbon exchange on a medium-to-large scale by blending eddy covariance flux data with …

Role Of Social Determinants Of Health In Differential Respiratory Exposure And Health Outcomes Among Children, Jagadeesh Puvvula, Jill A. Poole, Yeongjin Gwon, Eleanor G. Rogan, Jesse E. Bell

Daugherty Water for Food Global Institute: Faculty Publications

Background Attributes defining the Social Determinants of Health (SDoH) are associated with disproportionate exposures to environmental hazards and differential health outcomes among communities. The dynamics between SDoH, disproportionate environmental exposures, and differential health outcomes are often specific to micro-geographic areas.

Methods This study focused on children less than 20 years of age who lived in Douglas County, Nebraska, during 2016–2019. To assess the role of SDoH in differential exposures, we evaluated the association between SDoH metrics and criteria pollutant concentrations and the association between SDoH and pediatric asthma exacerbations to quantify the role of SDoH in differential pediatric asthma outcomes. …

Hydrodynamics And Sediment Transport In The Tidally Influenced James River, Ollie Gilchrest, Rip Hale

The Graduate School Posters

The tidally influenced James River is an important economic, ecologic, and cultural resource for VA residents. Tidal rivers have been historically understudied, however they are critical transition zones, the dynamics of which have implications for freshwater supply and sediment trapping. Globally, estimates suggest that >30% of fluvial sediment is trapped in the tidal zone, the location and dynamics of which are actively changing due to sea level rise and saltwater encroachment. In addition, analysis of historical water levels on the James River has shown a decrease in the tidal range since 1940. The present study combines >1-year’s worth of hydrographic …

The Use Of Transport Time Scales As Indicators Of Pollution Persistence In A Macro-Tidal Setting, Guanghai Gao, John J. O'Sullivan, Aisling Corkery, Zeinab Bedri, Gregory M.P. O'Hare, Wim G. Meijer

Articles

An understanding of water exchange processes is essential for assessing water quality management issues in coastal bays. This paper evaluates the impact of water exchange processes on pollution persistence in a macro-tidal semi-closed coastal bay through two transport time scales (TTS), namely residence time and exposure time. The numerical model was calibrated against field-measured data for various tidal conditions. Simulated current speeds and directions were shown to agree well with the field data. By considering different release scenarios of a conservative tracer by the refinement of an integrated hydrodynamic and solute transport model (the EFDC), the two TTS were used …

A Workshop On Using Nasa Airs Data To Monitor Drought For The U.S. Drought Monitor, Alireza Farahmand,, Sharon Ray, Heidar Thrastarson, Stephen Licata, Stephanie Granger, Brian Fuchs

National Drought Mitigation Center: Faculty Publications

Recent studies indicate that drought indicators based on near-surface air relative humidity (RH), air temperature (T), and air vapor pressure deficit (VPD), derived from the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite can detect the onset of drought earlier than other drought indicators, specifically standardized precipitation index (SPI), which is widely used for drought onset detection. A recent study showed that standardized relative humidity index (SRHI) can detect drought signals earlier than SPI (Farahmand et al. 2015). Relative humidity is a climate variable defined as the ratio of air vapor pressure to saturated vapor pressure. Precipitation and relative …

Trust And Subjective Knowledge Influence Perceived Risk Of Lead Exposure, Madeline Goebel, Chloe B. Wardropper

National Drought Mitigation Center: Faculty Publications

Lead exposure is a persistent environmental hazard that poses risks to human health. But motivating protective action is challenging with this low visibility hazard whose health effects are often subtle and chronic. Higher risk perception is generally associated with taking protective measures, so public health efforts prioritize risk messaging. Yet, little is known about perceptions of lead exposure risk among the U.S. public. Using cross-sectional data from a national survey of 1035 U.S. residents, we measured the role of trust in government management of lead and subjective knowledge about lead as predictors of perceived risk of lead exposure, controlling for …

Historical And Future Projections Of Supercell Precipitation Contributions To The Hydroclimate Of The United States, Aaron Zeeb

Graduate Research Theses & Dissertations

Rotating storms, or supercells, are frequent producers of significant tornadoes, hail, and nontornadic winds and an underappreciated genitor of extreme precipitation rates and flash floods. Little research has examined the precipitation contributions from supercells to the overall hydroclimate of the CONUS and, provided that these storms and their precipitation rates may shift in the future due to climate change, it is important to understand their characteristics from both historical and future perspectives. This research seeks to understand supercell precipitation characteristics across the CONUS using high-resolution, convection-permitting, dynamical-downscaled simulations for three, 15-year epochs. Epochs include a historical end-of-20th-century period (1990–2005) and …

Flood-Inundation Maps For An 8-Mile Reach Of Papillion Creek Near Offutt Air Force Base, Nebraska, 2022, Kellan R. Strauch, Christopher M. Hobza

United States Geological Survey: Water Reports and Publications

Digital flood-inundation maps for an 8-mile reach of Papillion Creek near Offutt Air Force Base, Nebraska, were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Air Force, Offutt Air Force Base. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Program website at https://www.usgs.gov/mission-areas/water-resources/science/flood-inundation-mapping-fim-program, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgages Papillion Creek at Fort Crook, Nebr. (station 06610795), and Papillion Creek at Harlan Lewis Road near La Platte, Nebr. (station 06610798). Near-real-time stages at these streamgages may …

Selected Anthropogenic Contaminants In Groundwater, Papio-Missouri River Natural Resources District, Eastern Nebraska, 1992–2020, Brent M. Hall, Cory L. Kavan, Amanda Flynn, Mikaela L. Cherry

United States Geological Survey: Water Reports and Publications

A study in cooperation with the Papio-Missouri River Natural Resources District was completed in 2019 to determine the concentration of contaminants of emerging concern (CEC) in groundwater in the Papio-Missouri River Natural Resources District, eastern Nebraska. Each well was sampled twice (in June and October or November) in 2019, totaling 34 samples. Samples were analyzed for 132 CECs, which include pharmaceutical, steroid hormone, and other organic chemicals. Seven of the 132 CEC analytes were detected in samples collected during this study. The most commonly detected CEC in this study was the antibiotic sulfamethoxazole. Other CECs detected in this study were …

An Integrated Hydrologic Model To Support The Central Platte Natural Resources District Groundwater Management Plan, Central Nebraska, Jonathan (Jp) Traylor, Moussa Guira, Steven M. Petersen

United States Geological Survey: Water Reports and Publications

The groundwater and surface-water supply of the Central Platte Natural Resources District supports a large agricultural economy from the High Plains aquifer and Platte River, respectively. This study provided the Central Platte Natural Resources District with an advanced numerical modeling tool to assist with the update of their Groundwater Management Plan.

An integrated hydrologic model, called the Central Platte Integrated Hydrologic Model, was constructed using the MODFLOW-One-Water Hydrologic Model code with the Newton solver. This code integrates climate, landscape, surface water, and groundwater-flow processes in a fully coupled approach. Model framework included 163 rows; 327 columns; 2,640 feet cell sides; …

Droughtscape, Winter 2023, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Winter 2023

Rad Rivers In Rad Places: Characterizing The Historical And Future Whitewater Resources In Select Regions Of The United States, Melissa D. Shafer

Graduate Theses, Dissertations, and Problem Reports (ETD)

Outdoor recreation is a highly profitable industry in the United States. In 2021, outdoor recreation accounted for $454.0 billion, or 1.9% of the current-dollar gross domestic product for the nation. Many states have benefited financially from focusing on promoting their outdoor recreation and natural resources. Whitewater (WW) paddling has been a recreational activity since the 1950s. In 2007 there were an estimated 1.2 million participants in whitewater kayaking. As of 2020, that number increased to 2.6 million, doubling the number of participants. WW resources can be leveraged to reshape local and regional economies. The framework developed in this study provides …

Historical And Forecasted Kentucky Specific Slope Stability Analyses Using Remotely Retrieved Hydrologic And Geomorphologic Data, Daniel M. Francis

Theses and Dissertations--Civil Engineering

Hazard analyses of rainfall-induced landslides have typically been observed to experience a lack of inclusion of measurements of soil moisture within a given soil layer at a site of interest. Soil moisture is a hydromechanical variable capable of both strength gains and reductions within soil systems. However, in situ monitoring of soil moisture at every site of interest is an unfeasible goal. Therefore, spatiotemporal estimates of soil moisture that are representative of in-situ conditions are required for use in subsequent landslide hazard analyses.

This study brings together various techniques for the acquisition, modeling, and forecasting of spatiotemporal retrievals of soil …

Soil Moisture And Geomorphologic Data For Use In Dynamic And Forecastable Landslide Hazard Analyses In Eastern Kentucky, Daniel M. Francis, L. Sebastian Bryson

Civil Engineering Research Data

These data are the geomorphologic and land information system-based soil moisture estimates from assimilation of NASA SMAP satellite-based observations and NOAH 3.6 Land Surface Model estimates over known landslides in Eastern Kentucky. Additionally Long Short-Term Memory Recurrent Neural Network and logistic regression machine learning codes, as well as an Application programming interface code are included. Finally, in-situ data from Eastern Kentucky is included.

Evaluating Benthic Macroinvertebrate Populations In Response To Scouring Events In The Trinity River, Ca, Liam Hay, Michael W. O'Neil, Chloe Pieper-Wasem

Environmental Science & Management Senior Capstones

River systems across California have been impacted by appurtenant structures such as dams and diversions. These structures have had an adverse impact on Benthic invertebrate (BMI) communities by regulating river systems and changing the natural hydraulic pulses that follow seasonal precipitation. Benthic invertebrates are a critical food resource for salmonids and serve as an indicator of ecosystem health. Our study was interested in seeing the effects of scouring events on BMI in the Trinity River of Trinity County, C.A. Following a large precipitation event that occurred in the region in December 2022, an influx of water entered the river through …

Drivers Of Spatiotemporal Patterns Of Surface Water Inputs In A Catchment At The Rain-Snow Transition Zone Of The Water-Limited Western United States, E. Trujillo, J. Mcnamara

Geosciences Faculty Publications and Presentations

Spatial and temporal dynamics of rainfall and snowmelt (i.e., surface water inputs, SWI) control soil moisture, groundwater recharge, and streamflow at annual, seasonal, and event scales. In the rain-snow transition zone, comprising a large portion of the mountainous western United States, there is limited understanding of the sensitivity of spatiotemporal SWI dynamics across hydrologically variable water years (WYs). We modeled rainfall and snowpack dynamics in a small headwater catchment (1.8 km²) spanning the rain-snow transition in southwestern Idaho, USA, for two hydrologically distinct WYs (2011 and 2014). In wet WY 2011 and dry WY 2014, total precipitation drove …

Spatiotemporal Retrievals Of Soil Moisture And Geomorphologic Data For Landslide Sites In Eastern Kentucky, Lindsey Sebastian Bryson, Daniel M. Francis

Civil Engineering Research Data

These data are the soil texture, land information system-based soil moisture estimates from assimilation of NASA SMAP satellite-based observations and NOAH 3.6 Land Surface Model estimates, artificial neural network machine learning code, and in-situ soil moisture measurements.

Delineating A Stream Network At Gale Crater, Mars, On Arcgis Pro: A Geographic Information Systems Approach, Elpidio Guzman De La Cruz

West Chester University Master’s Theses

The northwestern region of the Gale crater experienced flooding in the past. Delineation of stream networks for the northwestern region of Gale Crater, Mars employing geographic information systems (GIS) techniques is applied. The stream network produced by the algorithm in the study traverses the clay unit in Gediz Vallis, and visual HiRISE imagery analysis correlates with a topologic cross section of an inverted river channel of 750 meters wide and 90 meters deep. HiRISE imagery analysis further confirms a sulfate and clay stratigraphic unit in a stream 125 meters wide and 25 meters deep. Lastly, data smoothing procedures in the …

Nitrite Cycling In The Primary Nitrite Maxima Of The Eastern Tropical North Pacific, Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, Karen L. Casciotti

OES Faculty Publications

The primary nitrite maximum (PNM) is a ubiquitous feature of the upper ocean, where nitrite accumulates in a sharp peak at the base of the euphotic zone. This feature is situated where many chemical and hydrographic properties have strong gradients and the activities of several microbial processes overlap. Near the PNM, four major microbial processes are active in nitrite cycling: ammonia oxidation, nitrite oxidation, nitrate reduction and nitrite uptake. The first two processes are mediated by the nitrifying archaeal/bacterial community, while the second two processes are primarily conducted by phytoplankton. The overlapping spatial habitats and substrate requirements for these microbes …

Controls On Thermokarst Lake Water Balances In The Inuvik - Tuktoyaktuk Region, Evan J. Wilcox

Theses and Dissertations (Comprehensive)

There are tens of thousands of thermokarst lakes in the Inuvik-Tuktoyaktuk region, located in the northwest corner of the Northwest Territories, Canada. These lakes formed following the last glacial period in areas where ice-rich permafrost thawed and created depressions in the landscape. The Inuvik-Tuktoyaktuk region is one of the fastest warming regions in the world, leading to changing precipitation patterns, permafrost thaw and deciduous shrub expansion, all of which are affecting the water balance of thermokarst lakes. During the past several decades, lake expansion and contraction have been observed in response to fluctuations in precipitation. While these changes in lake …

Comparison Of Permafrost Thaw-Related Changes To Hydrological Response And Land Cover In Subarctic Peatland-Dominated Landscapes, Mikhail Mack

Theses and Dissertations (Comprehensive)

The hydrological implications of discontinuous permafrost thaw in peatland-dominated basins are not well understood. While there is evidence suggesting that permafrost-thaw-driven land cover change increases annual runoff and the runoff ratio in the Taiga Plains of northwestern Canada, few studies have evaluated the impact on small to medium-sized basins (< 10⁵ km²) outside this ecoregion. Here, we assess runoff, runoff ratio, and precipitation trends for 34 peatland-dominated basins, of which 28 are in the discontinuous and sporadic permafrost zones and 6 in adjacent permafrost-free environments. We calculated annual and monthly trends between 1970 and 2016 using the Mann-Kendall …