Hydraulic Engineering Commons^™

Bicp Global Bim Study - Lessons For Ireland’S Bim Programme, Barry Mcauley, Alan Hore, Roger West

Reports

The Construction IT Alliance (CitA) has been promoting the benefits of digitisation in the construction and engineering industry in Ireland since its formation back in 2002. Whilst the Alliance has always strived to ensure that its members are exposed to a wide spectrum of contemporary digital tools and processes, the concept of Building Information Modelling (BIM) has dominated the focus of its activities over the past five years.

BIM can be described as a digital tool that facilitates everybody to better understand a building or structure through the use of a digital model which draws on a range of data …

Road Zipper™, Purdue Ect Team

ECT Fact Sheets Archive

Construction work zones are growing in number around the world. The natural aging of existing roadway infrastructure ensures that more and more maintenance and rehabilitation will be required. Work zones, by their very definition, create two major problems that must be addressed in some way: safety and mobility. In the United States, highway work zones are responsible for almost 25% of all non-recurring congestion and 10% of overall congestion. Vehicle accidents are more common in work zones, and traffic congestion through work zones on urban arterials and freeways is often considered to be “unavoidable." To address these issues, ROAD ZIPPER™ …

Center Pivot Irrigation Handbook (Ec3017), Derrel Martin, William Kranz, Tyler Smith, Suat Irmak, Charles Burr, Ron Yoder

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Center pivot irrigation has been the most rapidly expanding form of irrigation in the Central Great Plains and across the United States. The amount of land irrigated with sprinkler, gravity and drip or trickle systems was determined for all states in the USA in the Farm and Ranch Irrigation Survey1 by the USDA in 2012. Results of the survey for the Great Plains States shows that approximately 85% of the land in Nebraska is irrigated with center pivots and that very little land was irrigated with drip systems in 2012 (Figure 1). The percentage of land irrigated with sprinklers in …

Effects Of Initial Aquifer Conditions On Economic Benefits From Groundwater Conservation, T. Foster, N. Brozovic, A. P. Butler

Daugherty Water for Food Global Institute: Faculty Publications

Worldwide, there is growing recognition of the need to reduce agricultural groundwater use in response to rapid rates of aquifer depletion. To date, however, few studies have evaluated how benefits of conservation vary along an aquifer’s depletion pathway. To address this question, we develop an integrated modeling framework that couples an agro-economic model of farmers’ field-level irrigation decisionmaking with a borehole-scale groundwater flow model. Unique to this framework is the explicit consideration of the dynamic reductions in well yields that occur as an aquifer is depleted, and how these changes in intraseasonal groundwater supply affect farmers’ ability to manage production …

Aquacrop-Os: An Open Source Version Of Fao’S Crop Water Productivity Model, T. Foster, N. Brozovic, A. P. Butler, C. M. U. Neale, D. Raes, P. Steduto, E. Fereres, T. C. Hsiao

Daugherty Water for Food Global Institute: Faculty Publications

Crop simulation models are valuable tools for quantifying crop yield response to water, and for devising strategies to improve agricultural water management. However, applicability of the majority of crop models is limited greatly by a failure to provide open-access to model source code. In this study, we present an open-source version of the FAO AquaCrop model, which simulates efficiently water-limited crop production across diverse environmental and agronomic conditions. Our model, called AquaCrop-OpenSource (AquaCrop-OS), can be run in multiple programming languages and operating systems. Support for parallel execution reduces significantly simulation times when applying the model in large geospatial frameworks, for …

In-Situ Observation And Transport Modelling Of Arsenic In Gangetic Plain, India, Pankaj Kumar Gupta, Pranjay Joshi, Jahangeer

Daugherty Water for Food Global Institute: Faculty Publications

The focus of this study is to investigate the arsenic movement and impacts on the residual concentrations on groundwater pollution load. The Gangetic plain area in the Ballia, Uttar Pradesh is selected as study area, which is also reported to extreme arsenic pollution in soil-water system. A modelling approach is developed to assess the arsenic flux in partially saturated zone using data of soil texture, soil hydraulic properties and stratigraphy. Soil type, slope, and land-use cover is considered for estimating the transient flux at the top boundary from daily precipitation and evapotranspiration data of the study area. Solute transport in …

Paid To Pump: How A Tax Credit Could Discourage Conservation Of The High Plains Aquifer, S. Polzkill,, A. Stejskal, H. Wilke, Anna Wistrom, Katherine E. B. Gibson, Mindy J. Spiehs, Nicholas Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

In 1965’s United States v. Shurbet case, an irrigator from Texas asserted his claim for a depletion tax deduction for groundwater pumped from the High Plains Aquifer. He argued that the unique conditions of the southern High Plains region - a plateau where the shallow aquifer is recharged only through precipitation at a slow rate - meant the groundwater resource would be depleted in time. The state argued that groundwater was not fundamentally an exhaustible natural deposit, but the Supreme Court concluded the tax deduction was appropriate given the “peculiar” conditions in the area. It was stated the decision was …

Pathways To Increasing Farmer-Led Investments In Sustainable Agricultural Water Management In Sub-Saharan Africa, Douglas J. Merrey, Peter G. Mccornick, Molly C. Nance

Daugherty Water for Food Global Institute: Faculty Publications

Without a transformative leap forward in the use of irrigation, Africa will continue falling short in the struggle to feed its growing population, improve its people’s nutrition, grow its economies, adapt to the impacts of climate change, and eliminate poverty. While Africans must lead this transformation for it to be successful, the international community can help African countries substantially increase the use of more productive and sustainable water management practices and unlock the potential of farmer-led irrigated agriculture. Achieving highly productive irrigated agricultural systems in Africa requires an enabling environment that facilitates the full engagement of farmers, public and private …

2017 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman

Nebraska Department of Environmental Quality: Reports

The Nebraska Department of Environmental Quality (NDEQ) is charged with monitoring, assessing, and to the extent possible, managing the state’s water resources. The purpose of this work is to protect and maintain high quality water and encourage or execute activities to improve poor water quality. Monitoring is done on nearly 17,000 miles of flowing rivers and streams, more than 134,000 acres of surface water in lakes and reservoirs, as well as the vast storage of groundwater in Nebraska’s aquifers.

High Performance Techniques Applied In Partial Differential Equations Library, Shilei Lin

All College Thesis Program, 2016-2019

This thesis explores various Trilinos packages to determine a method for updating the deal.ii library, which specializes in solving partial differential equations by finite element methods. It begins with introducing related concepts and general goals, followed by exploring computational and mathematical methods which are analytical solutions of one-dimensional Boussinesq equations and developing newer prototypes for solvers in deal.ii based on Trilinos packages. After demonstrating the methods, it indicates the reducing solving time in newer prototypes. Based on results from the prototype, similar methods are applied to update the deal.ii library. In the end, a testing program is exploited to demonstrate …

Impact Of Subsurface Drainage On Water Yield For Typical Soil And Weather In Eastern South Dakota, Govinda Karki

Electronic Theses and Dissertations

Subsurface drainage in agricultural land changes the field water balance by providing an alternate pathway for subsurface water. Determining the effects of subsurface drainage on downstream hydrology requires quantifying the components of the water balance. A number of studies have looked at the hydrological impacts of subsurface drainage. However, the effects are complex and difficult to generalize. The complex interaction involves the interrelation among variables such as soil type and properties, climate (rainfall and evapotranspiration), and drainage design configuration (drainage intensity and drainage coefficient), which all are local in nature. Additionally, most studies have been conducted in humid climates, whereas …

An Investigation Of The Hydraulics In A Prototype Pool-And-Chute, Vortex Weir Fishway For Anadromous Fish Passage., Brendan Foster

Cal Poly Humboldt theses and projects

This thesis presents the hydraulic characteristics and simulated passage efficiency of a hybrid pool-and-chute, vortex weir fishway designed by Michael Love & Associates. A physical 1:15 scale model was constructed and evaluated at an 8% slope over three prototype flow rates representing high and medium fish passage flows. The highest velocities and turbulent kinetic energy (TKE) values were concentrated along the fishway centerline at the high and medium flow rate and the pool sides showed lower velocities and TKE. Large eddies spin laterally and longitudinally throughout each pool. The velocity vector directions at the lowest flow rate measured differed from …

A Demonstration Study Of Drainage Water Management In Eastern South Dakota, Ashik Sahani

Electronic Theses and Dissertations

Subsurface drainage is a common water management practice for improving crop production in poorly drained soils; however, the practice is associated with several environmental concerns such as nutrient losses to downstream surface waters. These environmental concerns from subsurface drainage have prompted interest in drainage water management strategies such as controlled drainage. This study assessed the agronomic and environmental impacts of drainage water management in eastern South Dakota by using two demonstration plots for controlled and conventional drainage. Drain flow, nitrate and dissolved phosphorous concentration in drain water, shallow groundwater, crop yield, residual soil nitrate, soil moisture and temperature, soil penetration …

Evaluating Filter Materials For E. Coli Removal From Stormwater, Ghaem Hooshyari

Electronic Theses and Dissertations

Stormwater runoff from agricultural and urban areas carries a wide range of pollutants and pathogens that can negatively affect surface water bodies and cause significant risks to the ecosystem and public health. Bacteria is one of the pollutants carried by stormwater, and Escherichia coli (E. coli) is commonly used as a microbial pollution indicator of surface water. The aim of this research was to investigate the removal of E. coli from stormwater using low-cost filter materials. Two industrial byproducts (steel slag and steel chips) and two natural minerals (zeolite and limestone) with three different sizes (0.5-1 mm, 1-2 mm, and …

Nebraska Public Water Supply Program Summary Report 2017

Nebraska Department of Environmental Quality: Reports

The United States Environmental Protection Agency (EPA) established the Public Water System Supervision (PWSS) Program under the authority of the 1974 Safe Drinking Water Act (SDWA). Under the SDWA and the 1986 Amendments, EPA sets national limits on contaminant levels in drinking water to ensure that the water is safe for human consumption. These limits are known as Maximum Contaminant Levels (MCLs) and Maximum Residual Disinfectant Levels (MRDLs). For some regulations, EPA establishes treatment techniques in lieu of an MCL to control unacceptable levels of contaminants in water.

2017 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …

Compensatory Response Of Fathead Minnow Larvae Following A Pulsed In-Situ Exposure To A Seasonal Agricultural Runoff Event, Jonathan M. Ali, John Sangster, Daniel D. Snow, Shannon L. Bartelt-Hunt, Alan S. Kolok

Nebraska Water Center: Faculty Publications

Agriculturally-dominated waterways such as those found throughout the Midwestern United States often experience seasonal pulses of agrichemical contaminants which pose a potential hazard to aquatic organisms at varying life stages. The objective of this study was to characterize the developmental plasticity of fathead minnow larvae in a natural environment subject to a seasonal episodic perturbation in the form of a complex mixture of agricultural stressors. Fathead minnow larvae were maintained at the Elkhorn River Research Station for a 28-d in situ exposure to an agrichemical pulse event.Minnow larvae were sampled after 14 and 28 days to characterize developmental plasticity through …

Segment-Based Reliability Assessment For Water Distribution Networks, Erika Hernandez Hernandez

Theses and Dissertations--Civil Engineering

In recent years, water utilities have placed a greater emphasis on the reliability and resilience of their water distribution networks. This focus has increased due to the continuing aging of such infrastructure and the potential threat of natural or man-made disruptions. As a result, water utilities continue to look for ways to evaluate the resiliency of their systems with a goal of identifying critical elements that need to be reinforced or replaced. The simulation of pipe breaks in water reliability studies is traditionally modeled as the loss of a single pipe element. This assumes that each pipe has an isolation …

A Geospatial Variable Rate Irrigation Control Scenario Evaluation Methodology Based On Mining Root Zone Available Water Capacity, K. A. Miller, Joe Luck, Derek M. Heeren, T. Lo, Derrel Martin, J. B. Barker

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Increasing concern for sustainable water use has the agriculture industry working toward higher efficiency in use of irrigation water. Recent advancements have improved the capabilities of center pivot irrigation systems to vary water application depths across the field, a technology known as variable rate irrigation (VRI). The goal of this study was to provide a geospatial method for potential VRI technology adopters to evaluate control scenarios and potential water savings using freely available datasets. Root zone available water capacity (R) was estimated spatially across two case study fields using the Natural Resources Conservation Service Gridded Soil Survey Geographic Database. The …

Relative Sea-Level Trends In New York City During The Past 1500 Years, Andrew C. Kemp, Troy D. Hill, Christopher H. Vane, Niamh Cahill, Philip M. Orton, Stefan A. Talke, Andrew C. Parnell, Kelsey Sanborn, Ellen K. Hartig

Civil and Environmental Engineering Faculty Publications and Presentations

New York City (NYC) is threatened by 21st-century relative sea-level (RSL) rise because it will experience a trend that exceeds the global mean and has high concentrations of low-lying infrastructure and socioeconomic activity. To provide a long-term context for anticipated trends, we reconstructed RSL change during the past ~1500 years using a core of salt-marsh sediment from Pelham Bay in The Bronx. Foraminifera and bulk-sediment δ¹³C values were used as sea-level indicators. The history of sediment accumulation was established by radiocarbon dating and recognition of pollution and land-use trends of known age in down-core elemental, isotopic, and pollen …

การบริหารจัดการระบบอ่างเก็บน้ำภายใต้เงื่อนไขการพัฒนาระบบเศรษฐกิจในลุ่มน้ำแม่กลอง, เพ็ญนภา พีรวงศ์สกุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ลุ่มน้ำแม่กลองเป็นลุ่มน้ำที่สำคัญในภาคตะวันตกของประเทศไทย มีเขื่อนขนาดใหญ่วางขนานกันจำนวน 2 เขื่อน ได้แก่ เขื่อนศรีนครินทร์ และเขื่อนวชิราลงกรณ โดยทางด้านล่างมีเขื่อนทดน้ำอีกจำนวน 2 เขื่อน ได้แก่ เขื่อนท่าทุ่งนา และเขื่อนแม่กลอง สามารถผลิตกระแสไฟฟ้าเพื่อส่งเข้าระบบในช่วงการใช้ไฟฟ้าสูงสุดของภาคกลาง และภาคตะวันตกได้อย่างดี โดยในปัจจุบันพบว่าในปีน้ำปกติลุ่มน้ำแม่กลองมีปริมาณน้ำมากกว่าความต้องการใช้น้ำ สามารถผันน้ำเข้าช่วยเหลือโครงการชลประทานบริเวณลุ่มน้ำท่าจีน ผันน้ำเพื่อผลิตน้ำประปาที่โรงผลิตน้ำมหาสวัสดิ์ และผันน้ำเพื่อช่วยผลักดันน้ำเค็มทางตอนล่างของลุ่มน้ำ แต่ในปีน้ำน้อยพบว่าลุ่มน้ำแม่กลองมีการขาดแคลนน้ำในลุ่มน้ำเป็นจำนวนมาก โดยเฉพาะภาคเกษตรกรรม ขาดแคลนน้ำผลักดันน้ำเค็มท้ายลุ่ม และรวมถึงปัญหาปริมาณน้ำในเขื่อนต่ำจนไม่สามารถผลิตกระแสไฟฟ้าได้ ในปัจจุบันเขื่อนทั้ง 4 เขื่อนในโครงการพัฒนาแหล่งน้ำในลุ่มน้ำแม่กลองนั้น มีการบริหารจัดการน้ำที่เป็นอิสระต่อกัน ทั้งที่อ่างเก็บน้ำเหล่านั้นเชื่อมต่อกันด้วยแม่น้ำแควใหญ่ และแม่น้ำแควน้อย ซึ่งสามารถบริหารจัดการน้ำร่วมกันเพื่อให้ได้ประโยชน์สูงสุดภายใต้ข้อจำกัดที่มี วัตถุประสงค์ของการศึกษานี้คือการพัฒนาแบบจำลองการบริหารจัดการระบบอ่างเก็บน้ำ (multi - reservoir) โดยการหาแนวทางการบริหารจัดการน้ำที่เหมาะสมกับเป้าหมาย (objective function) ภายใต้เงื่อนไขการพัฒนาเศรษฐกิจของลุ่มน้ำ ในการวิจัยนี้ได้ศึกษาความสัมพันธ์ความสัมพันธ์ระหว่างตารางปัจจัยการผลิตและผลผลิต (Input - Output Table) และความต้องการใช้น้ำ ของ 3 ภาคส่วนเศรษฐกิจ ได้แก่ ภาคส่วนเกษตรกรรม ภาคส่วนอุตสาหกรรม และภาคส่วนบริการ ซึ่งเป็นวิธีการใหม่ในการพิจารณามูลค่าของน้ำ สามารถหาผลประโยชน์ทั้งทางตรง ทางอ้อม และกิจกรรมในห่วงโซ่อุปทานอุปสงค์ของระบบเศรษฐกิจตามความต้องการใช้น้ำของแต่ละภาคส่วนได้ โดยแบบจำลองของระบบอ่างเก็บน้ำลุ่มน้ำแม่กลองเป็นปัญหาแบบไม่เป็นเชิงเส้นจํานวนผสม (MINLP) การศึกษานี้ได้พัฒนาแบบจำลองการบริหารจัดการระบบอ่างเก็บน้ำในโปรแกรม GAMS ใช้โปรแกรมแก้ปัญหาสำร็จรูป BONMIN โดยจะพิจารณาการบริหารจัดการน้ำในปี พ.ศ. 2556 - 2557 ซึ่งเป็นปีน้ำปกติ และน้ำน้อยตามลำดับ มีสมการเป้าหมาย (objective function) ที่พิจารณาผลประโยชน์ทางเศรษฐศาสตร์ของน้ำที่ส่งไปให้ใช้ประโยชน์ดังนี้ น้ำเพื่อการเกษตร น้ำเพื่อการประปาโรงผลิตน้ำมหาสวัสดิ์ น้ำเพื่อภาคอุตสาหกรรมในลุ่มน้ำ น้ำเพื่อภาคบริการในลุ่มน้ำ และพลังงานไฟฟ้าจากโรงไฟฟ้าพลังงานน้ำจากเขื่อนที่พิจารณา จากการศึกษาพบว่าการบริหารจัดการอ่างเก็บน้ำร่วมกันสามารถลดการขาดน้ำของภาคเกษตรได้ถึงร้อยละ 80 สามารถผลิตไฟฟ้าจากพลังงานน้ำได้มากขึ้นร้อยละ 0.70 และสามารถเพิ่มผลประโยชน์ทางเศรษฐศาสตร์เมื่อเทียบกับการบริหารจัดการจริงได้ถึงร้อยละ 10.10 ในปีน้ำปกติ ส่วนในปีน้ำน้อยสามารถลดการขาดน้ำของภาคเกษตรได้ถึงร้อยละ 58.56 สามารถผลิตไฟฟ้าจากพลังงานน้ำได้มากขึ้นร้อยละ 16.15 และสามารถเพิ่มผลประโยชน์ทางเศรษฐศาสตร์ได้ถึงร้อยละ 4.36

Air Injection As A Scour Countermeasure At Bridge Piers, Ravi Teja Reddy Tippireddy

Dissertations, Master's Theses and Master's Reports

Local scour is a major cause of concern for the stability of bridge piers and the safety of the public using the bridges. Structural countermeasures and flow-altering devices have been developed to deal with local scour. Many armoring structural countermeasures are very effective and efficient in clear water conditions but are susceptible to moving bed forms and leaching. The flow-altering devices are effective in both clear water conditions and moving bed forms, but are prone to clogging, less efficient in changing flow direction, etc. This study aims to reduce the local scour by injecting air in order to reduce the …

A Validated Tropical-Extratropical Flood Hazard Assessment For New York Harbor, Philip M. Orton, T. M. Hall, Stefan A. Talke, Alan F. Blumberg, Nickitas Georgas, S. Vinogradov

Civil and Environmental Engineering Faculty Publications and Presentations

Recent studies of flood risk at New York Harbor (NYH) have shown disparate results for the 100 year storm tide, providing an uncertain foundation for the flood mitigation response after Hurricane Sandy. Here we present a flood hazard assessment that improves confidence in our understanding of the region's present-day potential for flooding, by separately including the contribution of tropical cyclones (TCs) and extratropical cyclones (ETCs), and validating our modeling study at multiple stages against historical observations. The TC assessment is based on a climatology of 606 synthetic storms developed from a statistical-stochastic model of North Atlantic TCs. The ETC assessment …

Hydraulic And Hydrologic Properties Of The Sabine River, Annie L. Bryant

Civil Engineering Theses

The Sabine River is located in Northeast Texas and is home to many threatened and endangered species as well as a growing human population. It is important to understand channel properties and flow characteristics of rivers in order better manage these important natural resources. The Sabine was monitored for hydraulic and hydrological properties as this is a poorly understood river at this point in time.

Hydraulic modeling was conducted to determine channel velocities and shear stresses during different storm frequencies. It was found that velocity and shear stress had a direct relationship at lower velocities. A comparison of existing Geographic …

Lucidpipe™ Power System, Purdue Ect Team

ECT Fact Sheets Archive

In most gravity fed water transmission pipelines, it is desired to reduce excess pressure head to prevent undue strain on a pipeline and lower the incidence of leaks. Normally this is done with pressure reducing valves that essentially burn off this excess pressure as heat. The LucidPipe™ system converts it to low cost electricity thereby removing unwanted pressure and generating energy at the same time - energy that can be put used behind the grid or put back on the grid. The LucidPipe™ system extracts a small percentage of pressure head providing nearly invisible operation allowing water operators to fulfill …

Benchmark Levels For The Consumptive Water Footprint Of Crop Production For Different Environmental Conditions: A Case Study For Winter Wheat In China, La Zhuo, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Meeting growing food demands while simultaneously shrinking the water footprint (WF) of agricultural production is one of the greatest societal challenges. Benchmarks for the WF of crop production can serve as a reference and be helpful in setting WF reduction targets. The consumptive WF of crops, the consumption of rainwater stored in the soil (green WF), and the consumption of irrigation water (blue WF) over the crop growing period varies spatially and temporally depending on environmental factors like climate and soil. The study explores which environmental factors should be distinguished when determining benchmark levels for the consumptive WF of crops. …

Evaluating The Mechanisms Of Erosion For Coarse-Grained Materials, Maureen K. Corcoran, Ghada Ellithy, Michael K. Sharp, Johannes L. Wibowo

Publications

Efforts are currently underway by the U.S. Army Corps of Engineers (USACE) to perform a risk assessment of all dams and levees within their portfolio. The vast majority of that portfolio is earthen structures. Findings from the assessments have shown that the major risk drivers for these earth structures are related to erosion (internal and external), overtopping, poorly designed and constructed intrusions (such as pipe crossings), and other factors to a lesser degree (such as burrowing animals). Therefore, the USACE is currently investigating several of these failure modes with emphasis on internal and external erosion. This paper will highlight efforts …

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. …

Laboratory And Full Boom-Based Investigation Of Nozzle Setup And Restriction Effects On Flow, Pressure And Spray Pattern Distribution, Shane H. Forney

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Pesticide application is an integral part of crop production and ground-based agricultural boom sprayers are used extensively to apply pesticides to the crop canopy or soil surface across millions of acres in the United States. Efficient application is necessary to minimize costs and limit adverse environmental impacts. Errors in flow rate and system pressure measurements may cause as-applied maps to incorrectly indicate application rates and could negatively affect downstream data processing or analysis. The goals of this study were to provide quantified measurements on the effects of nozzle setup errors on spray pattern uniformity and evaluate how laboratory patternator data …

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 …