Environmental Engineering Commons^™

Investigating The Prediction Of High Resolution Heat Waves And Extreme Precipitation And The Impact Of Heat Waves On Air Quality In U.S. In The 21st Century, Yang Gao

Doctoral Dissertations

In this study, the perennial problem of scale is addressed with an updated set of modeling tools that include global climate, atmospheric chemistry simulation, mesoscale weather, and air quality simulations. The evaluation of coupled model performance across geographic scales and the assessment of local scale climate change impacts under a fossil fuel intensive climate change scenario Representative Concentration Pathway (RCP 8.5) was achieved by linking the global climate model Community Earth System Model (CESM), with the regional climate model Weather Research and Forecasting (WRF) Model. This study is the first evaluation of dynamical downscaling using WRF on a 4km by …

Impacts Of Beetle Kill On Modeled Streamflow Response In The North Platte River Basin, Jordan Andrew Rudolph

Masters Theses

A beetle epidemic has been sweeping its way across the western United States and into portions of southern Canada that has caused millions of acres of forests to ultimately die. This beetle outbreak, that many have come to know simply as “beetle kill”, has caused many scientists to feel that such dramatic changes in land cover could potentially alter the hydrology throughout much of the West. One of the most important hydrological processes that beetle kill has the potential to impact is streamflow. This paper attempts to evaluate the hydrological impacts on streamflow from land cover change due to beetle …

Exploring Anaerobic Reductive Dechlorination At Low Ph Environments, Yi Yang

Masters Theses

Chlorinated aliphatic hydrocarbons (CAHs), such as tetrachloroethene (PCE) and trichloroethene (TCE), are ubiquitously pollutants in aquifer sediments and groundwater due to their heavy usage in industry and inappropriate disposal in the last century. Among about 1300 NPL (National Priorities List) sites, PCE and TCE are the two most frequently detected hazardous contaminants.

Engineered bioremediation, including biostimulation and bioaugmentation, is a promising technology to clean those PCE and/or TCE contaminated sites. However, in many contaminated groundwater systems and hazardous waste sites, pH can be lower than 5 to 6. And release of HCl (strong acid) from anaerobic reductive dechlorination may lower …

Utilization Of Rainwater As A Supplementary Water Source For Cooling Tower Makeup: A Sustainability Strategy For Potable Water Use Reduction, Elizabeth Stassun Costello

Masters Theses

The use of rainwater as a supplementary water source for cooling water makeup was explored in an effort to reduce the potable water demand of theUniversityofTennessee’sKnoxvillecampus. A water quality analysis involving the measurement of parameters relevant to cooling tower operation was conducted on tap water currently used for makeup supply and rainwater collected from the roof of a campus building. In anticipation of limited rainwater supplies due to issues of catchment surface area, collection efficiency, storage capacity, and climatic conditions, blends of rainwater and tap water were also analyzed. The dissolved solids concentration of the rainwater was significantly lower than …

Estimates Of Glacier Mass Loss And Contribution To Streamflow: Wind River Range (Wyoming, Usa), Jeffrey Allen Marks

Masters Theses

The Wind River Range is a continuous mountain range approximately 160 km in length in west-central Wyoming. The Wind River Range is host to roughly 680 snow and ice bodies with 63 of these considered glaciers including seven of the ten largest glaciers in the American Rocky Mountains. The presence of glaciers results in meltwater contributions to streamflow during the late summer (July, August, and September – JAS) when snowmelt is decreasing, temperatures are high, precipitation is low, and irrigation demand continues. Most studies indicate that the glaciers in the Wind River Range have been retreating since the 1850’s, the …

Study Of The Driving Cycle For Heavy Duty Trucks In Hilly Terrain And Its Effect On Calculated Emissions, And Comparison Of Two Mobile Emission Models, Jeongran Yun

Doctoral Dissertations

Vehicle emissions were estimated using MOVES2010a and MOBILE6.2 for a Pittsburgh case study involving a modal shift in freight transportion. MOVES2010a (hereafter referred to as MOVES) is currently the USEPA official mobile source emissions computer model; it replaced the older model, MOBILE6.2. Changing the method of hauling freight from highway to waterway is the transport modal shift. Results from this part of the study showed that emission estimates for all vehicle types using MOVES were higher than emissions estimated using MOBILE6.2/NMIM for CO, NO_X, PM₁₀, PM_2.5, and VOC, but emissions were lower for CO …

Hydrologic Reconstructions Using Dendroclimatology, Climate Signals, And Pacific Ocean Sea Surface Temperature Variability, Sallyrose Anderson

Doctoral Dissertations

The Colorado River provides water to over 25 million people. Given the importance of this water supply, it is critical to understand the hydrologic variables in the Colorado River Basin. In this dissertation, I reconstructed hydrologic conditions (soil moisture, snowpack) in the Upper Colorado River Basin (UCRB) and examined different factors that influence water supply in the region (climate oscillations, oceanic-atmospheric variability).

Firstly, I reconstructed soil moisture in the UCRB. Principal components analysis (PCA) and k-Nearest Neighbor (k-NN) techniques were used to regionalize the gridded data. Correlated tree-ring chronologies (TRCs) were used as predictor variables in stepwise linear regression (SLR) …

Hydrology, Soil Erosion And Climate Interactions On Low Compaction Steep-Sloped Reclaimed Sites In The Southern Appalachian Coal Fields, Tennessee, Siavash Hoomehr

Doctoral Dissertations

The use of loose spoil on steep slopes for surface coal mining reclamation sites has been promoted by the US Department of Interior, Office of Surface Mining for the establishment of native forest. Although low-compaction spoils improve tree survival and growth, the erodibility and hydrology of steep slopes may change due to this practice. The purpose of this study was to quantify the erodibility (K factor), and the Curve Number (CN) value for low compaction, steep-sloped (> 20%) reclaimed mine lands in the Appalachian region, USA. This study also investigated the performance of the SEDCAD model in estimating erosion and …

Anticipated Changes In Precipitation Events Over The 21st Century Using Community Climate System Model, Version 4, Scott Tavish Deneale

Masters Theses

Future global daily precipitation data from Community Climate System Model, version 4 (CCSM4) were analyzed to evaluate changes in a variety of precipitation parameters over the 21st century. Multiple ensemble members of 21st century Representative Community Pathways (RCP) radiative scenarios were included in the model to provide an array of potential future climate change results. Multiple ensembles of historic daily precipitation data from CCSM4 were compared with Global Precipitation Climatology Project (GPCP) V1DD daily precipitation data and Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) monthly precipitation data. Annual average and 95th percentile precipitation values were averaged from 1997-2005 …

Analysis Of Georeferenced Sonar-Based Thalweg And Cross-Sectional River Depth Profile Measurements, Kenneth Wray Swinson

Masters Theses

Depth is a physical river characteristic that is important for habitat classification, river health analysis, and hydrologic/hydraulic modeling. Recent studies have shown that sonar can be an accurate way of measuring river depth, when compared to traditional techniques, but more study is necessary. The main objective of this research was to evaluate the utility of the CruzPro ATU120S and the Lowrance LMS-350A sonar depth units as tools for collecting river depth measurements along longitudinal (thalweg) and cross-sectional profiles. This included analyzing and evaluating the georeferenced commercially available sonar units for accuracy, precision, and response time under controlled lab and river …

Soil Nitrification And Mineralization Rates Along An Elevation Gradient In The Great Smoky Mountains National Park, Christopher James Rolison

Masters Theses

The Great Smoky Mountains National Park (GRSM) is an area sensitive to acid deposition. Although reports indicate there have been reductions of acid deposition in the eastern United States, water quality in streams has not recovered to perceived natural levels. Coupled soil biogeochemical processes of nitrification and nitrogen mineralization can acidify soil water and play a key role in the fate of nitrogen-based acid deposition and observed stream acidification. Characterizing nitrogen decomposition rates at different elevations improves our understanding of the potential effects of acid deposition and soil interactions with acid ions. Soil chemical properties and potential reaction rates for …

A Comparison Of 7q10 Low Flow Between Rural And Urban Watersheds In Eastern United States, Saeed Zabet

Masters Theses

Abstract: Increased runoff peaks and volumes from urbanizing watersheds have been well documented where watershed hydrology becomes modified after 10 to 25% of land area is developed. Lowering of baseflow has also been reported to be modified from urbanization; however hydrology thresholds related to percentage of land area developed are not well quantified. In this study, 100 watersheds in eastern USA were investigated to examine the potential effects of urbanization on low flows. The low flow metric chosen for this analysis is the 7Q10. Historical flow records were obtained from the USGS stream gauges, in which a minimum of 10 …