Physical Sciences and Mathematics Commons^™

Policy Design Tool For Managing Indoor Residential Water Demand In Water-Scarce Regions, Mujahed M. Thneibat

Open Access Dissertations

In view of population growth; climate change; and economic evolution, water resources in numerous parts of the world have reached their natural capacities. Consequently, the ability of many countries to grow; meet the basic needs of inhabitants; and protect the environment will be endangered like never before unless water resources are smartly handled and managed. ^ In the past few decades, many developed and developing countries have suffered from water scarcity, and more are certain to follow. The water security dilemma is much more challenging in developing countries. Water utilities have had to follow regulatory plans to manage demand on …

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 …

A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly

Graduate Theses and Dissertations

Groundwater depletion, a subject of growing concern for a significant portion of Arkansas, may lead to future economic challenges for the Arkansas Delta region. The Mississippi River Valley Alluvial Aquifer is the uppermost aquifer and features the largest groundwater capacity in the Mississippi Embayment Aquifer System. The Mississippi River Valley Alluvial Aquifer, commonly referred to as the “alluvial aquifer”, spans 53,000〖 km〗^2 underlying portions of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Illinois, and Tennessee. As the alluvial aquifer trends southward for approximately 250 miles alongside the Mississippi River, its geographical extent ranges from 50 to 125 miles wide. There is a …

Nutrient Runoff And Leachate After Land-Application Of Digestate In A Laboratory Study Using Rainfall Simulations, Min Xiao

Open Access Theses

There has been an increasing number of anaerobic digesters on livestock farms in the United States during the past two decades. Anaerobic digestion of manure allows production of renewable energy and generation of stabilized and nutrient-rich digestate that can be used as organic fertilizer. However, the majority of the existed studies using liquid digestate as fertilizer only focused on the effectiveness for crop yield, nutrient content and microorganism in soil. There is insufficient understanding in the environmental impact of digestate land-application. This laboratory study used six treatments including four different liquid digestate treatments, a chemical fertilizer treatment, and an unfertilized …

Role Of River Bathymetry In Hydraulic Modeling Of River Channels, Sayan Dey

Open Access Theses

Accurate geometric representation of the river channel is required for accurate hydraulic modeling of rivers. These are generally obtained through remote sensing techniques such as Light Detection and Ranging (LIDAR). However, these techniques lack the ability to model the submerged channel bed effectively and need to be complemented with surveyed bathymetric data for complete representation of the channel bathymetry, which can be time and cost prohibitive. An alternative to address this issue is to develop conceptual models that can estimate bathymetry.

This study aims to evaluate the potential of a conceptual model, the River Channel Morphology Model (RCMM) which estimates …

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …

Optical Water Quality And Human Perceptions Of Rivers, Amie West

Graduate Theses and Dissertations

Understanding water quality dynamics in recreational rivers is integral in shaping management strategies that maintain ecosystem health, perceived value and appeal, and regional economic significance in a changing environment. Optical water quality describes the behavior of light in water as governed by its physical and chemical composition, and is among the strongest influences on human perceptions of water quality. Ethnohydrology is the study of culturally constructed knowledge and understanding of water. This work is the culmination of an interdisciplinary approach to water resources research—integrating optical water quality and ethnohydrology methods to recognize the intersection between measured water quality and visible …

Chlorine Demand Shows Thresholds And Hierarchy With Source Water Quality At Beaver Lake, Arkansas, Jaime M. Gile

Graduate Theses and Dissertations

This study investigated the effects of source water quality in Beaver Lake on the amount of chlorine (Cl) needed to develop decision support system to help guide chlorination practices in pre-treatment of source water. Chlorine demand assays were performed on water samples from Beaver Lake collected from the intake structure at Beaver Water District from March 2014 through August 2015, and using data from these assays, the two points of interest in this study were the Cl dose at which Cl residuals began to accumulate and the mean Cl demand occurring after that dose. Three methods of analysis were used …

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …

Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise

Graduate Theses and Dissertations

A steady-state mass diffusion model used with simple measurable and calculable inputs for determining sediment oxygen demand (SOD) is compared to an intact core incubation (ICI) SOD method using samples from three lakes. The mass diffusion model coupled with inputs is known as the measure-calculate method (M-C) and is a potential alternative to existing methods for measuring SOD which are more complex, time-consuming, and costly. The M-C method requires inputs for volumetric sediment oxygen uptake (Ṅsed), sediment density and porosity, and water properties. Ṅsed was determined by suspending sediment in oxygen-saturated water with a DO probe and determining the steady …

Asbestos Cement Pipe Condition Assessment And Remaining Service Life Prediction, Abiy Melles Ghirmay

Graduate Theses and Dissertations

This research details a condition assessment of asbestos cement (AC) pipe within in the Bella Vista Village Property Owners Association water distribution system. Bella Vista Village contains appropriately 300 miles of AC pipe with nominal diameters from 6-14 inch. The goal of the research is to determine the current condition of AC pipe within the system and predict future performance of the pipes. AC pipe samples were obtained from 23 locations disturbed across the distribution system with nominal pipe diameters of 6-8 inch. Estimates of current level of degradation were obtained using phenolphthalein staining and hardness measurements of each sample. …

Investigation Of Climate Variability And Climate Change Impacts On Corn Yield In The Eastern Corn Belt, Usa, Ruoyu Wang

Open Access Dissertations

The increasing demand for both food and biofuels requires more corn production at global scale. However, current corn yield is not able to meet bio-ethanol demand without jeopardizing food security or intensifying and expanding corn cultivation. An alternative solution is to utilize cellulose and hemi-cellulose from perennial grasses to fulfill the increasing demand for biofuel energy. A watershed level scenario analysis is often applied to figure out a sustainable way to strike the balance between food and fuel demands, and maintain environment integrity. However, a solid modeling application requires a clear understanding of crop responses under various climate stresses. This …

Simulation Of Conservation Practice Effects On Water Quality Under Current And Future Climate Scenarios, Carlington W. Wallace

Open Access Dissertations

Analysis of the effects of implementing different conservation practices, as well as increased levels of conservation practices under existing and projected future climate, will determine if current conservation practice recommendations will be sufficient to maintain soil and water resources. The Soil and Water Assessment Tool (SWAT) was used to study four watersheds of different sizes (CCW = 680 km2, F34 = 183 km2, AXL = 42 km 2 and ALG = 20 km2) located in Northeastern Indiana. The overarching goal of this study was to evaluate the effect of various agricultural practices on runoff and agricultural chemical losses under current …

Algal Wastewater Treatment And Biofuel Production: An Assessment Of Measurement Methods, And Impact Of Nutrient Availability And Species Composition, John F. Chamberlin

Graduate Theses and Dissertations

In order to move towards a more sustainable future, human civilization will need to decrease its impacts on air and water quality and minimize consumption of fossil fuels. Using algae for wastewater treatment and biofuel production offers one approach to progress towards these goals simultaneously. Algae are capable of removing nutrients from wastewater and carbon dioxide from the air, and the biomass formed in that process can be used to generate a wide-range of products including fertilizer or fuels that could power combustion engines, power plants, or zero-emission fuel cell vehicles. Using wastewater for biofuel production has the potential to …

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 …

Hydrologic And Water Quality Impacts From Perennial Crop Production On Marginal Lands, Qingyu Feng

Open Access Dissertations

Marginal lands are proposed as a viable option for producing biofeedstocks as these lands are not heavily engaged in agricultural production or may not be suitable for intensive row-crop food/feed production. However, meeting biofeedstock production goals will require large amount of marginal lands and the unintended consequences of producing biofeedstocks on marginal lands are not fully clear. The overall goal of this study was to evaluate the productivity of biofeedstocks on marginal lands and the potential impacts on hydrologic and water quality processes from the land use conversion.

This study was conducted in the Upper Mississippi River Basin (UMRB). First, …