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 …

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 …