Physical Sciences and Mathematics Commons^™

Willingness To Pay For Irrigation Water Under Scarcity Conditions, Tyler Robert Knapp

Graduate Theses and Dissertations

Reliance of Arkansas agricultural producers on groundwater for irrigation has led to depletion of the Mississippi River Valley alluvial aquifer. Without intervention, consequences include insufficient groundwater to meet irrigation demand as well as drawdown of the deeper Sparta Aquifer, upon which communities in eastern Arkansas rely for non-agricultural use. Among proposed solutions to combat groundwater decline is the construction of off-farm surface water infrastructure to meet the irrigation needs of producers. Despite the importance of irrigated agriculture to Arkansas, there is little know about the economic value of irrigation water to producers. Thus, we implement a double-bounded dichotomous choice contingent …

Behavioral Responses And Policy Evaluation: Revisiting Water And Fuel Policies, Shanxia Sun

Open Access Dissertations

In my dissertation, I examine how policies regulating agricultural production and clean technology impact the environment. I focus on policies affecting water depletion, water pollution, and fuel consumption. I assess their cost-effectiveness by modeling and quantifying the behavioral responses of farmers and households.

My first essay focuses on decreasing groundwater depletion through increasing irrigation efficiency in Mexico. I quantify the impacts of different sources of inefficiency on groundwater extraction, and I evaluate the effectiveness of alternative policies that aim to reduce the over-extraction of groundwater. I find that mechanisms of electricity cost-sharing implemented in many wells have a sizable impact …

Watershed Delineation In The Field: A New Approach For Mobile Applications Using Lidar Elevation Data, Samuel Adam Noel

Open Access Theses

With the advancement of mobile devices, opportunities to take watershed management tasks out of the office and into the field can be realized. In turn, field workers can utilize these technologies to expedite the decision-making process so that they may focus on meeting with clients and addressing agricultural watershed management issues. High-resolution (∼1.5 m postspacing) elevation data gathered by light detection and ranging (LiDAR) provides the topographic detail necessary to model hydrology at the field-scale (∼1 km2).

Non-artifactual surface depressions lead to erroneous surface flow patterns when using existing algorithms. So a sequential depression-filling algorithm (SDFA) has been developed to …

Leaching Characteristics Of Selenium From Coal Fly Ash, Mark Allen Cantrell

Graduate Theses and Dissertations

Selenium (Se) contamination can be a potential groundwater concern near un-lined coal ash landfills. Out of all the Environmental Protection Agency (EPA) priority and non-priority pollutants, Se has the narrowest range between what is considered beneficial and detrimental for aquatic and terrestrial organisms. The effects of ash type (i.e., fresh and weathered), water-extractant type (i.e., deionized water, rainwater, and groundwater), and extraction time (i.e., 2- and 6-hours) on Se, arsenic (As), and chromium (Cr) concentrations were investigated from Class C, subbituminous coal fly ash produced at the Flint Creek Power Plant located in Benton County, AR. Water-extractable Se concentrations differed …

Developing White Ash With Resistance To The Emerald Ash Borer, Kaitlin Joy Palla

Open Access Theses

Hypocotyls isolated from mature embryos germinated on Murashige and Skoog (MS) medium supplemented with 22.2 µM 6-benzyladenine (BA) and 0.5 µM thidiazuron (TDZ) were transformed using Agrobacterium tumefaciens strain EHA105 harboring the pBI121-8D2 vector containing the neomycin phosphotransferase (nptII) gene and a full length, codon-optimized Bacillus thuringiensis Cry8Da protoxin gene (cry8D2). Explants were transformed in a bacterial suspension with 100 µM acetosyringone using 90 s sonication and 10 min vacuum-infiltration. Four independent lines of transformed shoots were selectively regenerated on MS medium with 22.2 µM BA, 0.5 µM TDZ, 50 mg L^-1 adenine sulfate, 10% …

Habitat Restoration Of A Constructed Ohio River Embayment, Caleb Michael Rennaker

Open Access Theses

Backwater habitats of large rivers provide habitat for aquatic biota and influence important predator-prey interactions in fishes and other aquatic organisms. However, these areas often exhibit turbid conditions and lack habitat complexity. Restoration of lentic habitats through direct habitat manipulations has shown success in prior efforts, but these methods have not been tested in backwater habitats of large rivers. I attempted to create habitat in an Ohio River embayment by establishing founder colonies of aquatic macrophytes coupled with the placement of underwater gravel beds. I also evaluated the effects of total suspended solids (TSS) on overwintering structures of American Pondweed …

A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh

Graduate Theses and Dissertations

This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …

Assessing The Impacts Of Surface Water Removal For Use In Natural Gas Extraction On A Watershed Level, Carrie Ann Davis

Graduate Theses and Dissertations

In this study, the Soil and Water Assessment Test (SWAT) was used as a tool to predict whether diffuse water removal from the Cadron Creek watershed for use with natural gas development would have an impact on downstream flow within the watershed. Cadron Creek watershed expands across four counties within Arkansas and is located in the Fayetteville Shale Gas region. This region is experiencing significant growth in natural gas development. Successful development of shale gas depends on the identification of what water supplies are available for production without interfering with community and environmental needs. The SWAT model used to evaluate …

Livestock Production And Wildlife-Based Tourism: Articulating Land-Use And Policy Conflicts In The Okavango Delta Ramsar Site In Botswana, Nelson Kgamanyane Sello

Graduate Theses and Dissertations

The management of common pool resources and policy conflicts between livestock and wildlife, two land-use types that take place in the same geo-spatial area has been a subject of debate among scholars for decades. This conflict in policies has engendered in communities which are beneficiaries attitudes that are either negative towards wildlife or favorable depending on the benefits they derive from them. This research therefore set out to understand the conflicts in the management of the Okavango Delta Ramsar Site (ODRS) where the OD is situated. The study used the grounded theory to collect and analyze the data in the …

Integrating Human Variables In Cross-Boundary Monitoring Of Aberdare Preserves In Kenya, Peter K. Njuguna

Graduate Theses and Dissertations

This research critically examines extant data systems and their linkage of scientific research to policy and public education in east African highland forest conservation preserves. The research indicates that the current state of data and monitoring systems in the region imposes substantial limitations on the ability to manage these preserves. Major outcomes of those constraints manifest in unprecedented cross-boundary pressure such as encroachment and conversion of forest to agriculture, increased human-wildlife conflicts, and constrained relations among primary stakeholders. Current monitoring is biodiversity focused within preserves and fails to capture human dimensions in adjoining areas across preserve boundaries. This study proposes …

Recommendations For The Chamlidere Petrified Forest Management Plan, Fatma Ertem

Graduate Theses and Dissertations

Anything inherited from our ancestors or from nature can be considered as our heritage. Heritage can be classified as cultural and natural heritage. Turkey has been the cradle of many civilizations, religions, and ethnic groups because of the unprecedented natural heritage and critical geopolitical location of Anatolia. Given all the treasure of cultural and natural heritage in Turkey, heritage management practices have not been emphasized as they deserve. A petrified forest was found in Chamlidere, Ankara (Turkey) in 2004. Chamlidere petrified forest preserves information related to the biodiversity of forests in the Galatian Volcanic Province during the Early-Middle Miocene. When …