Engineering Commons^™

Low-Level Groundwater Atrazine In High Atrazine Usage Nebraska Counties: Likely Effects Of Excessive Groundwater Abstraction, Moses New-Aaron, Olufemi P. Abimbola, Raheleh Mohammadi, Oluwaseun Famojuro, Zaeema Naveed, Azar M Abadi, Jesse E. Bell, Shannon Bartelt-Hunt, Eleanor G. Rogan

Department of Biological Systems Engineering: Papers and Publications

Recent studies observed a correlation between estrogen-related cancers and groundwater atrazine in eastern Nebraska counties. However, the mechanisms of human exposure to atrazine are unclear because low groundwater atrazine concentration was observed in counties with high cancer incidence despite having the highest atrazine usage. We studied groundwater atrazine fate in high atrazine usage Nebraska counties. Data were collected from Quality Assessed Agrichemical Contaminant Nebraska Groundwater, Parameter–Elevation Regressions on Independent Slopes Model (PRISM), and water use databases. Descriptive statistics and cluster analysis were performed. Domestic wells (59%) were the predominant well type. Groundwater atrazine was affected by well depth. Clusters consisting …

Forecasting Nigeria's Electricity Demand And Energy Efficiency Potential Under Climate Uncertainty, Olawale Olabisi

Doctoral Dissertations

The increasing population and socio-economic growth of Nigeria, coupled with the current, unmet electricity demand, requires the need for power supply facilities expansion. Of all Nigeria’s electricity consumption by sector, the residential sector is the largest and growing at a very fast rate. To meet this growing demand, an accurate estimation of the demand into the future that will guide policy makers to adequately plan for the expansion of electricity supply and distribution, and energy efficiency standards and labeling must be made. To achieve this, a residential electricity demand forecast model that can correctly predict future demand and guide the …

Modeling Watershed Sensitivity To Climate Change In Systems Affected By Discharge Of Mine Tailings, Johnette C. Shockley

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

For more than a century, a large volume of gold-mining tailings was deposited in Whitewood Creek and the Belle Fourche River, tributaries to the Cheyenne River in western South Dakota. Much of it still remains, and field and historical evidence indicates continued remobilization of tailings-containing alluvium in these bedrock-dominated channels. Both long-term, natural fluctuations in climate and anthropogenically driven changes can impact regional precipitation, temperature, hydrologic patterns, and ecosystem functions. Such changes have the potential to affect both the transport and distribution of arsenic-laden sediments and mechanical erosion that can undermine the stability of channel-bed and overbank material.

This study …

Utility Scale Building Energy Modeling And Climate Impacts, Brett C. Bass

Doctoral Dissertations

Energy consumption is steadily increasing year over year in the United States (US). Climate change and anthropogenically forced shifts in weather have a significant impact on energy use as well as the resilience of the built environment and the electric grid. With buildings accounting for about 40% of total energy use in the US, building energy modeling (BEM) at a large scale is critical. This work advances that effort in a number of ways. First, current BEM approaches, their ability to scale to large geographical areas, and global climate models are reviewed. Next, a methodology for large-scale BEM is illustrated, …

Compound Extremes Drive The Western Oregon Wildfires Of September 2020, John T. Abatzoglou, David E. Rupp, Larry W. O'Neill, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Several very large high‐impact fires burned nearly 4,000 km² of mesic forests in western Oregon during September 7–9, 2020. While infrequent, very large high‐severity fires have occurred historically in western Oregon, the extreme nature of this event warrants analyses of climate and meteorological drivers. A strong blocking pattern led to an intrusion of dry air and strong downslope east winds in the Oregon Cascades following a warm‐dry 60‐day period that promoted widespread fuel flammability. Viewed independently, both the downslope east winds and fuel dryness were extreme, but not unprecedented. However, the concurrence of these drivers resulted in compound extremes …

Optical And Physicochemical Properties Of Atmospherically Processed Brown Carbon Using Novel First-Principle Instrumentation, Benjamin Sumlin

McKelvey School of Engineering Theses & Dissertations

Atmospheric processing of brown carbon (BrC) – a class of spherical, internally-mixed, light-absorbing organic aerosol – emitted from smoldering biomass combustion is an understudied phenomenon with implications for climate science, air quality models, and satellite retrieval algorithms. BrC aerosols have received significant attention as a strong contributor to atmospheric light absorption in the shorter visible wavelengths and a driver of UV photochemistry. Their complex refractive indices (m=n+ik), size distributions, and carbon oxidation states dictate their optical properties, atmospheric residence times, and chemical interactions, respectively. There is currently a gap in our understanding of these fundamental particle properties and their evolution …