Engineering Commons^™

Biogeochemical Modeling Of The Response Of Forest Watersheds In The Northeastern U.S. To Future Climate Change, Afshin Pourmokhtarian

Dissertations - ALL

In this dissertation I assessed the potential hydrochemical responses of future climate change conditions on forested watersheds in the northeastern U.S. using climate projections from several atmosphere ocean general circulation models (AOGCMs) under different carbon dioxide (CO2) emissions scenarios. The impacts of changing climate on terrestrial ecosystems have been assessed by observational, gradient, laboratory and field studies; however, state-of-the-art biogeochemical models provide an excellent tool to investigate climatic perturbations to these complex ecosystems. The overarching goal of this dissertation was to apply a fully integrated coupled hydrological and biogeochemical model (PnET-BGC) to evaluate the effects of climate change and increasing …

An Investigation Into The Water Budget And The Management Of The Snake River System, John Whitney Hildreth

Boise State University Theses and Dissertations

Future climate change poses a major conceptual challenge to the availability of water resources due to the uncertainty involved with changes to the hydrologic cycle. Over the past decades, observed warming temperatures across the Western United Sates have shown significant impacts on river basin scale hydrology. This research uses physically based modeling tools to assess the hydrologic impacts of climate change in the Snake River Basin. Physically based hydrologic modeling studies of future climate do not typically take into account interactions between groundwater and surface water. To account for these interactions, the Variable Infiltration Capacity model is coupled with the …

Hydraulic Impact Of Porosity Distribution And Hydrologic Characterization Of Porous Pavements, William Martin

All Dissertations

This research focused on the hydrologic characterization of porous pavement and pavement properties that can affect its hydraulic behavior. The first of these properties investigated was the presence of a vertical porosity distribution which can significantly impact the infiltration rate. A method utilizing image analysis was tested and experimentally verified. The representative elemental area (REA) was needed for this imaging method and was found to be 83.9 cm2 (13 in2). To convert the porosity distribution into a permeability distribution the relationship between porosity and permeability was found using homogenous samples. From the resulting permeability distribution an effective permeability was found …

Hydrologic Characterization Of A Rain Garden Mitigating Stormwater Runoff From A Commercial Area, John T. Mcmaine

Theses and Dissertations--Biosystems and Agricultural Engineering

Impervious surfaces such as roads, sidewalks, and roofs increase the volume of runoff generated in a watershed. Traditional stormwater management techniques emphasize conveyance of runoff away from impervious surfaces in order to reduce flooding. Rain gardens are becoming popular as a different means to manage stormwater in such a way that runoff is captured and infiltrated onsite rather than conveyed offsite. A stormwater management system consisting of a rainwater harvest system, rain garden, and infiltration chamber was built at the Coca-Cola Refreshments USA, Inc. distribution center in Lexington, Kentucky during the fall of 2011. Precipitation, inflow, and water level were …

Biomass Production And Hydrological/Water Quality Impacts Of Perennial Crop Production On Marginal Land, Qingyu Feng

Open Access Theses

Marginal land has been proposed to be a viable choice for biomass production to meet the biofuel development goal set by Energy Independence and Security Act (EISA). However, very little information is currently available for quantifying biomass production potential and impacts on hydrology and water quality. The objectives of this study were to: (1) quantify availability of marginal land in a typical agricultural watershed; (2) test whether the biomass feedstock produced from marginal land in the study watershed can support a hypothetical small bio-refinery with annual capacity of 50 million gallons of ethanol produced; and (3) evaluate the hydrological/water quality …

Using Gis To Delineate Headwater Stream Origins In The Appalachian Coal-Belt Region Of Kentucky, Jonathan A. Villines

Theses and Dissertations--Biosystems and Agricultural Engineering

Human activity such as surface mining can have substantial impacts on the natural environment. Performing a Cumulative Hydrologic Impact Assessment (CHIA) of such impacts on surface water systems requires knowing the location and extent of these impacted streams. The Jurisdictional Determination (JD) of a stream’s protected status under the Clean Water Act (CWA) involves locating and classifying streams according to their flow regime: ephemeral, intermittent, or perennial. Due to their often remote locations and small size, taking a field inventory of headwater streams for surface mining permit applications or permit reviews is challenging. A means of estimating headwater stream location …

Syntactic And Semantic Interoperability Among Hydrologic Models, Mostafa Mohamed Elag

Theses and Dissertations

Development of integrated hydrologic models requires coupling of multidisciplinary, independent models and collaboration between different scientific communities. Component-based modeling provides an approach for the integration of models from different disciplines. A key advantage of component-based modeling is that it allows components to be created, tested, reused, extended, and maintained by a large group of model developers and end users. One significant challenge that must be addressed in creating an integrated hydrologic model using a component-based approach is enhancing the interoperability of components between different modeling communities and frameworks. The major goal of this work is to advance the integration of …

Watershed-Scale Hybrid Stochastic-Deterministic Modeling Framework And Diffused Sources Superpositioning, Ruby Juvah Damalie

Civil & Environmental Engineering Theses & Dissertations

Predicting hydrologic system behavior is imperative to planning and management of water resources. The study developed an integrated hybrid stochastic and deterministic framework to improve prediction accuracy for overland flow and diffused sources in a watershed. The methodology includes sampling input parameters at system level and contribution of nonpoint source from hydrologically disconnected areas (heretofore referred to as system-level approach and superpositioning respectively). System-level approach includes the integration of a topography-based sampling grid generalized linear model developed by the study and Monte Carlo methods. The superpositioning method adopts in-stream water quality equation for overland flow pollution estimation.

The system-level approach …