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Spatial Response Of Near-Surface Soil Water Contents To Newly Imposed Soil Management, Aaron L. M. Daigh, Upasana Ghosh, Jodi DeJong-Hughes, Robert Horton 2018 North Dakota State University--Fargo

Spatial Response Of Near-Surface Soil Water Contents To Newly Imposed Soil Management, Aaron L. M. Daigh, Upasana Ghosh, Jodi Dejong-Hughes, Robert Horton

Agronomy Publications

Near-surface soil water content (SWC) and its spatial patterns are important for landscape hydrological responses to precipitation as well as our ability to remotely sense and model such responses. Our objective was to measure and evaluate near-surface SWC semivariograms of agricultural fields with newly imposed (i.e., <2 yr) side-by-side soil and residue management practices (i.e., reduced tillage systems and cover crops) in the midwestern United States. Range parameters were consistently smaller when cover crops were planted (20–25 m less) and tillage area and/or intensity was reduced (12–27 m less) compared with no cover crop and chisel plowing, respectively, except in a clayey Vertisol. Nugget and sill parameters did not have consistent trends across soil management practices or sites. These data, although brief and preliminary in scope, provide clear proof of concept that spatial pattern shifts can be clearly detected in newly imposed soil-management systems even though differences in SWC means are not always evident.


Spatial And Temporal Trends Of Mining-Related Lead-Zinc Sediment Contamination, Galena River Watershed, Sw Wisconsin-Nw Illinois, Dylan Alexander King 2018 Missouri State University

Spatial And Temporal Trends Of Mining-Related Lead-Zinc Sediment Contamination, Galena River Watershed, Sw Wisconsin-Nw Illinois, Dylan Alexander King

MSU Graduate Theses

Alluvial sediments within the Galena River Watershed were severely contaminated with heavy metals by historical zinc (Zn) and lead (Pb) mining operations during the early 1800s until 1979. Since the mines closed, there have been efforts to remediate on-site mine waste. However, the effectiveness of these efforts to reduce metal concentrations in stream sediments is unknown. This study compares present-day (2017) contamination trends in the Galena River Watershed to trends reported 25 years ago. A total of 415 sediment/soil samples were collected and analyzed using X-ray florescence spectrometry to determine sediment metal concentrations. The highest concentrations of zinc measured ...


Nutrient Transport And Storage In A Karst Spring-Reservoir System During Baseflow, Missouri Ozarks, Heather A. Moule 2018 Missouri State University

Nutrient Transport And Storage In A Karst Spring-Reservoir System During Baseflow, Missouri Ozarks, Heather A. Moule

MSU Graduate Theses

Urban and agricultural land uses are important sources of nitrogen and phosphorus which, if in excess, can cause eutrophication in lakes and rivers. There have been few studies of nutrient transport and storage in karst spring and reservoir connected stream systems draining the Missouri Ozarks. This study aims to link the baseflow nutrient contributions of Sanders Spring to downstream reservoir outflow and the Headwaters South Dry Sac River Watershed in Springfield, Missouri. Water samples were collected seasonally and analyzed for total nitrogen (TN), total phosphorus (TP), and several other water quality parameters. Discharge was also monitored to calculate water and ...


From Snow To Flow: Exploring Relationships Between Snotel Ablation Curves And Peak Streamflow Timing, Kara Jane Ferguson 2018 Boise State University

From Snow To Flow: Exploring Relationships Between Snotel Ablation Curves And Peak Streamflow Timing, Kara Jane Ferguson

Boise State University Theses and Dissertations

Predictions of peak streamflow timing in snow-dominated river systems are essential for proper water management and recreational availability. This study evaluates historic snow and streamflow data from 14 river basins throughout Idaho to investigate the relationship between snowmelt timing at SNOw TELemetry (SNOTEL) sites and peak streamflow within each basin. The goal is to provide a simple operational tool that estimates the probability of peak streamflow occurring within a certain number of days as ablation progresses from 0 to 100% melted. For individual basins we evaluate meltout levels in increments of 10% from each SNOTEL site and use a probabilistic ...


Evaporation Depth Controls The Relationship Between Soil Water Mobility And Soil Water Isotopic Composition, John Byars Shuler 2018 Boise State University

Evaporation Depth Controls The Relationship Between Soil Water Mobility And Soil Water Isotopic Composition, John Byars Shuler

Boise State University Theses and Dissertations

Recent studies of plant water uptake assume that soil water isotopic composition can be used to infer soil water mobility. However, the strength of the relationship between mobility and isotopic composition remains poorly constrained. In addition, many ecohydrologic investigations are restricted by low sampling frequencies and insufficient soil moisture and matric potential data to support assumptions of soil water mobility. We sampled bulk soil water every 14 to 21 days in hillslope and riparian profiles during the 2016 and 2017 growing seasons in a semi-arid watershed outside Boise, ID. We collected twig samples of four tree and shrub species concurrently ...


Exploring The Role Of Deforestation On Regional Hydroclimate In Southeast Africa: An Approach Fusing Models And Data, Megan Maksimowicz 2018 Boise State University

Exploring The Role Of Deforestation On Regional Hydroclimate In Southeast Africa: An Approach Fusing Models And Data, Megan Maksimowicz

Boise State University Theses and Dissertations

Land cover acts as the gatekeeper to incoming and outgoing energy and water fluxes at the land surface, partitioning energy and water in accordance with the vegetation type and in response to atmospheric forcings. As Land Surface Models become more complex and more capable of simulating the coupled dynamics of the land-atmosphere system in greater spatial detail, the need for accurate representation of spatial distribution of vegetation types and their dynamics through time grows.

As humans modify land cover, there are complex dynamics at play between the vegetation, the surface energy balance and the cycling of water. The resultant hydroclimatic ...


Assessment Of Snow Atmosphere Forcing During Central Idaho Atmospheric Rivers, William Rudisill 2018 Boise State University

Assessment Of Snow Atmosphere Forcing During Central Idaho Atmospheric Rivers, William Rudisill

Boise State University Theses and Dissertations

Atmospheric Rivers (AR) are globally occuring weather features and the primary mechanism through which water vapor moves from the tropics and subtropics towards the mid-latitudes, doing so at rates comparable to the world’s largest terrestrial rivers. AR that encounter mountains often cause extreme precipitation in the form of rain and snow, high winds, and flooding in many watersheds. They account for as much as 20-30% of cool season precipitation in the central Idaho Mountains. In the Northern Hemisphere, seasonal snow cover during Winter and Spring months is the most variable land surface component in space and time, and acts ...


A Comparison Of Vnir And Mir Spectroscopy For Predicting Various Soil Properties, Joshua R. Gates 2018 University of Nebraska-Lincoln

A Comparison Of Vnir And Mir Spectroscopy For Predicting Various Soil Properties, Joshua R. Gates

Dissertations & Theses in Natural Resources

Soil plays an important role in our daily lives, namely producing food, cleaning water and storing carbon. The ability to rapidly and cost-effectively quantify the various components of soils can help us understand and better manage this important resource. This study aims to compare the ability of visible near-infrared (VNIR) spectroscopy and mid-infrared (MIR) spectroscopy to quickly and accurately predict various important soil properties (electrical conductivity, soil pH, cation exchange capacity, exchangeable cations, phosphorus, carbon, beta-glucosidase enzyme activity and nitrogen). Prediction models were developed using partial least squares regression (PLSR) techniques. Three different calibration sampling methods were tested along with ...


Distribution And Habitat Association Of The Northern Long-Eared Bat, Zachary A. Warren 2018 University of Nebraska - Lincoln

Distribution And Habitat Association Of The Northern Long-Eared Bat, Zachary A. Warren

Dissertations & Theses in Natural Resources

Because of white-nose syndrome, the northern long-eared bat (Myotis septentrionalis) is experiencing rapid population declines across the majority of its range. This decline has prompted increased regulatory protection and thus an increased need for effective habitat management strategies. Insight into the species habitat associations, however, is a prior necessity to ensure management practices are biologically relevant. Understanding these relationships requires a holistic approach that addresses the multiple ways in which the species is interacting with its environment. The objective of my thesis was to address these relationships following a multi-scale approach that assessed the factors associated with roost tree selection ...


Boundary Spanners And Trust Development Between Stakeholders In Integrated Water Resource Management: A Mixed Methods Study, Jodi L. Delozier 2018 University of Nebraska-Lincoln

Boundary Spanners And Trust Development Between Stakeholders In Integrated Water Resource Management: A Mixed Methods Study, Jodi L. Delozier

Dissertations & Theses in Natural Resources

Natural resource issues are inherently complex, even more so are those that involve the management of water. Because watersheds tend to cross multiple jurisdictional and geographical boundaries, a diverse set of stakeholders are needed to develop appropriate and sustainable management policy. This research sheds light on the importance of boundary spanners assisting in the development of trust between stakeholders in integrated water resource management (IWRM). Previous literature has explored the advantages to boundary spanning leadership in business practice, emergency management, university and community management as well as fish and wildlife management, but has failed to address the area of integrated ...


Estimating Watershed Mercury Contribution To Lake Fort Smith State Park, Arkansas, Usa, William Miles Harmon 2018 University of Arkansas, Fayetteville

Estimating Watershed Mercury Contribution To Lake Fort Smith State Park, Arkansas, Usa, William Miles Harmon

Theses and Dissertations

Mercury contamination associated with human activities poses global human health and environmental risks. A fish-consumption advisory has been in effect at Lake Fort Smith in central west Arkansas for more than a decade due to observed methylmercury concentrations in fish tissue. Lake Fort Smith is an important municipal drinking water supply and recreational resource. Water samples from the majority contributing tributary stream, Frog Bayou creek, were collected periodically, under differing hydrologic conditions in order to quantify the allochthonous mercury load delivered to the lake. Temperature, specific conductance, and turbidity data were collected and used to estimate dissolved organic carbon, methylmercury ...


Comparative Microbial Community Dynamics In A Karst Aquifer System And Proximal Surface Stream In Northwest Arkansas, Josue Rodriguez 2018 University of Arkansas, Fayetteville

Comparative Microbial Community Dynamics In A Karst Aquifer System And Proximal Surface Stream In Northwest Arkansas, Josue Rodriguez

Theses and Dissertations

Northwest Arkansas has well-developed karst systems, with numerous sinking streams and springs. Karst conduits make it easy for contaminants to enter groundwater systems, degrading the water quality and destroying fragile karst ecosystems. With the increase of urbanization, potential threats in the form of fecal contamination may prove to be more of a problem. The purpose of this research is to compare the difference between microbial communities within two different settings, a karst aquifer and a surface stream. The microbial communities within Blowing Spring Cave and Little Sugar Creek were detected and identified in water and sediment samples. Samples were also ...


Testing An Improved Method For Estimating The Unsaturated Hydraulic Conductivity Of Moderately Dry Soils, Sara Gedo 2018 University of Nevada, Las Vegas

Testing An Improved Method For Estimating The Unsaturated Hydraulic Conductivity Of Moderately Dry Soils, Sara Gedo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Prediction of water movement in the vadose zone requires knowledge of either the unsaturated hydraulic conductivity, K(θ), or the hydraulic diffusivity, D(θ), of the soil as a function of the moisture content. However, both K(θ) and D(θ) are difficult to obtain for moderately dry soils because the tests are time consuming and expensive. In order to address this issue, Globus and Gee (1995) developed a “heat pipe” method that allowed for the direct estimation of D(θ) and K(θ) for moderately dry soils on relatively short time scales. They proposed that exposing a sealed horizontal ...


Quantifying Carbon Dioxide Fluxes In The Air And Water In Blowing Springs Cave, Arkansas, Holly Young 2018 University of Arkansas, Fayetteville

Quantifying Carbon Dioxide Fluxes In The Air And Water In Blowing Springs Cave, Arkansas, Holly Young

Theses and Dissertations

Prior work has shown that the concentration of carbon dioxide (CO2) within cave atmospheres is a function of cave airflow patterns. The dynamics of CO2 within karst systems are of increasing interest as they can control periods of precipitation or dissolution in speleothems and influence potential interpretations of paleoclimate records. Similarly, CO2 is an important driver of speleogenesis, and air-water CO2 dynamics can control patterns of cave passage evolution. Karst also plays an uncertain role in the global carbon cycle and understanding CO2 dynamics within karst systems will aid the development of carbon budgets. Here, a monitoring station was deployed ...


Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, Allyn Dodd 2018 University of Arkansas, Fayetteville

Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, Allyn Dodd

Theses and Dissertations

The natural flow regime exerts primacy over lotic ecosystem patterns and processes. However, little work has examined the influence of flow regime on instream and riparian carbon (C) dynamics in minimally-impacted, temperate forested systems. To date, most research efforts have focused on characterizing C movement and transformations across biomes and land use categories; however, flow regime represents an overlooked, finer level of detail that may drive differences in ecosystem function. My dissertation objective was to measure C fixation and movement within and across multiple environmental spheres (e.g. within stream channels, between stream surfaces and the atmosphere, and from riparian ...


Approaches For Estimating Soil Water Retention Curves At Various Bulk Densities With The Extended Van Genuchten Model, Zhengchao Tian, Weida Gao, Dilia Kool, Tusheng Ren, Robert Horton, Joshua L. Heitman 2018 North Carolina State University

Approaches For Estimating Soil Water Retention Curves At Various Bulk Densities With The Extended Van Genuchten Model, Zhengchao Tian, Weida Gao, Dilia Kool, Tusheng Ren, Robert Horton, Joshua L. Heitman

Agronomy Publications

Soil bulk density (ρb) variations influence soil hydraulic properties, such as the water retention curve (WRC), but they are usually ignored in soil-water simulation models. We extend the van Genuchten WRC model parameters to account for ρb variations using a series of empirical expressions. WRC measurements made on eight soils with various ρb and textures are used to calibrate these ρb–related empirical equations. Accordingly, two approaches are developed to estimate WRCs of soils at various ρb. Another eight soils with a wide range of ρb and textures are used to evaluate the accuracy of the new approaches. Approach 1 ...


Tiered Approaches In Analyzing Rice Field Pesticide Fate And Transport For Ecological Risk Assessment, Ruoyu Wang 2018 University of California, Davis

Tiered Approaches In Analyzing Rice Field Pesticide Fate And Transport For Ecological Risk Assessment, Ruoyu Wang

Ruoyu Wang

No abstract provided.


Estimating Adaptation To Climate Change In Groundwater Irrigation, James Keeler 2018 University of Nebraska-Lincoln

Estimating Adaptation To Climate Change In Groundwater Irrigation, James Keeler

Dissertations and Theses in Agricultural Economics

Understanding the adaptive capacity of irrigated agriculture, including to what extent producers adjust irrigation choices along the intensive and extensive margins, is vital to the development of accurate and holistic estimates of the impacts of climate change on agricultural production and the sustainability of water-related ecosystem services. This thesis proposes and implements a natural experiment using statistical matching methods to estimate how producers adjust groundwater extraction, irrigated crop acreage, and irrigation technology in response to long-term changes in precipitation and evapotranspiration. Results from groundwater irrigated fields in Kansas suggest that intensive and extensive margin water use adaptations are generally limited ...


Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown 2018 Stephen F. Austin State University

Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown

International Journal of Speleology

Diverse karst phenomena occur throughout the Gypsum Plain where the Castile Formation crops out over ~1800 km2 in West Texas and southeastern New Mexico. Hypergene karst is extensive and widespread, while traditional hypogene karst manifestations (both caves and intrastratal dissolution) occur in high frequency in the western outcrop region where surface denudation has been the greatest so as to induce surficial breaching. Unconfined hypogene karst occurrences have been recently identified, including two general variations: 1) artesian-like discharge features; and 2) venting structures. Artesian-like discharge features arise at surficially-breached hypogene caves and through high permeability regions on the margins of ...


High Net Loss Of Intertidal Wetland Coverage In A Maine Estuary By Year 2100, Jack R. McLachlan 2018 UMaine

High Net Loss Of Intertidal Wetland Coverage In A Maine Estuary By Year 2100, Jack R. Mclachlan

Biology and Ecology Faculty Scholarship

Rising sea levels and coastal land use are predicted to synergistically impact coastal wetlands by reducing their extent and ecosystem functioning through a process known as “coastal squeeze”. Impervious surfaces associated with coastal development prevent the natural process of wetland migration, whereby intertidal wetland area is lost at its seaward edge to rising low water lines, but is replaced by eroding uplands and accumulating new wetland at its landward edge. As these constructed surfaces prevent the replacement of lost wetland, intertidal wetlands are “squeezed” by rising sea levels until they disappear. This study uses geographic information system (GIS) to predict ...


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