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Full-Text Articles in Physical Sciences and Mathematics
Willingness To Pay For Irrigation Water Under Scarcity Conditions, Tyler Robert Knapp
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 …
The Role Of Organic Matter In The Fate And Transport Of Antibiotic Resistance, Metals, And Nutrients In The Karst Of Northwest Arkansas, Victor Lee Roland Ii
The Role Of Organic Matter In The Fate And Transport Of Antibiotic Resistance, Metals, And Nutrients In The Karst Of Northwest Arkansas, Victor Lee Roland Ii
Graduate Theses and Dissertations
Organic matter (OM) in the environment acts as a nutrient, but may also act as a transport vector for harmful chemical compounds and bacteria. Acetate is a labile form of OM produced during fermentation in anaerobic lagoons used to store animal fecal-waste from concentrated animal feeding operations (CAFOs). Dry and liquid fertilizers from CAFOs pose a threat to groundwater by introducing excessive amounts of nutrients (e.g. OM, nitrate and ammonia), metals, and antibiotic compounds. In the epikarst of Northern Arkansas in the Buffalo River watershed additional input of labile dissolved organic carbon (DOC) from liquid CAFO waste-fertilizers was hypothesized to …
Water Source Partitioning For Shrubland Transpiration In A Mixed Phreatophytic Plant Community, Amanda Jean Wagner
Water Source Partitioning For Shrubland Transpiration In A Mixed Phreatophytic Plant Community, Amanda Jean Wagner
UNLV Theses, Dissertations, Professional Papers, and Capstones
Groundwater in the basins of east central Nevada (Great Basin Desert, NV) has been permitted for export to southern Nevada. These basins are also vulnerable to changes in climate that could lead to declining recharge. Any decline in groundwater levels no matter the driving force could significantly impact phreatophytes (deep rooted shrubs), which utilize water from both the vadose zone and the capillary fringe to meet plant water needs, to support growth, and for overall health. A reduction in groundwater due to these forces could have a significant impact on the decoupling of phreatophytes from what is normally a reliable …
Impacts To Anadromous Fish Through Groundwater Extraction, Aaron Hebert
Impacts To Anadromous Fish Through Groundwater Extraction, Aaron Hebert
Master's Projects and Capstones
California uses more groundwater than any other state in the United States in order to meet agricultural demand during the growing season when water is naturally least available due to the state’s Mediterranean climate. The state also hosts populations of anadromous fish that are otherwise found exclusively in the wetter Pacific northwest. Groundwater has historically helped maintain baseflow in the summer and fall low-flow periods and acted as a natural buffer against the regular droughts that occur in California. Today, groundwater provides 30-40% of the state’s water supply, but the pumping in many cases has reduced groundwater discharge and baseflow, …
High Capacity Wells And Baseflow Decline In The Wolf River Basin, Northeastern Wisconsin, Susan A. Borchardt
High Capacity Wells And Baseflow Decline In The Wolf River Basin, Northeastern Wisconsin, Susan A. Borchardt
Theses and Dissertations
The baseflow of the Wolf River (drainage area of 1 200 km2) in northeastern Wisconsin has declined by over 30% during the last thirty years, whereas climatic, land cover, and soil characteristics of the basin have remained unchanged. Because groundwater basins do not always coincide with surface water basins, estimating groundwater discharge to streams using variables only pertinent to the surface water basin can be ineffective. The purpose of this study is to explain the decline in the baseflow of the Wolf River by developing a multiple regression model. To take into account variables pertaining to the groundwater basin, withdrawal …
Sources Of Water And Solutes To The Salar De Atacama, Chile: A Coupled Hydrologic, Geochemical, And Groundwater Modeling Study, Lilly G. Corenthal
Sources Of Water And Solutes To The Salar De Atacama, Chile: A Coupled Hydrologic, Geochemical, And Groundwater Modeling Study, Lilly G. Corenthal
Masters Theses
Focused groundwater discharge in endorheic basins provides opportunities to investigate mechanisms for closing hydrologic budgets in arid regions. The Salar de Atacama (SdA), a closed basin in northern Chile, has accumulated over 1800 km3 of halite and a lithium-rich brine since the late Miocene primarily through evapotranspiration of groundwater. The hydrologic balance of SdA and sources of water and solutes required to explain this deposit are not well constrained. An adapted chloride mass balance method drawing on a database of over 200 water sample sites is applied to a remotely-sensed precipitation dataset to estimate spatially-distributed modern groundwater recharge. Comparing …
Mobility Of Escherichia Coli Within Karst Terrains, Kentucky, Usa, Ashley M. Bandy
Mobility Of Escherichia Coli Within Karst Terrains, Kentucky, Usa, Ashley M. Bandy
Theses and Dissertations--Earth and Environmental Sciences
Bacterial contamination of karst aquifers is a concern as water quality across the globe deteriorates in the face of decreasing water security. This study examined the transport and attenuation of two non-virulent isolates of Escherichia coli in relation to traditional groundwater tracers such as rhodamine WT dye and latex microspheres in two karst regions in Kentucky. Differential movement between the four tracers was observed in both epikarst and karst aquifer traces, with differences in behavior dependent on flow conditions. Attenuation was greater for the bacterial isolate containing the iha gene, compared to the isolate containing the kps gene. Microspheres of …
Global And Regional Assessments Of Unsustainable Groundwater Use In Irrigated Agriculture, Danielle S. Grogan
Global And Regional Assessments Of Unsustainable Groundwater Use In Irrigated Agriculture, Danielle S. Grogan
Doctoral Dissertations
Groundwater is an essential input to agriculture world-wide, but it is clear that current rates of groundwater use are unsustainable in the long term. This dissertation assesses both current use of groundwater for country- to global-scale agriculture, and looks at the future of groundwater. The focus is on 1) quantifying food directly produced as a result of groundwater use across spatially-varying agricultural systems, 2) projecting future groundwater demands with consideration of climate change and human decision-making, and 3) understanding the system dynamics of groundwater re-use through surface water systems. All three are addressed using a process-based model designed to simulate …
Adapting Near-Ultraviolet Colorimetry For Long-Term In Situ Monitoring Of Hexavalent Chromium In Groundwater Aquifers, Janine Carter
Adapting Near-Ultraviolet Colorimetry For Long-Term In Situ Monitoring Of Hexavalent Chromium In Groundwater Aquifers, Janine Carter
Graduate Student Theses, Dissertations, & Professional Papers
This paper briefly describes sources of hexavalent chromium [Cr(VI)] and the risk it poses to human health and the environment; current methods used to regulate, monitor, and measure Cr(VI); the basic design of a submersible, direct-reading sensor in development for long-term monitoring of Cr(VI) concentration in natural waters; and the means developed to correct sensor readings for two common analytical interferences, turbidity and pH, that could lead to an incorrect measurement of Cr(VI). The principal purposes of this study are to analyze the current methods used to compensate for sample turbidity, to develop methods to compensate for sample pH, and …