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 …

A System Dynamics Approach To Water Resources And Food Production In The Gambia, Jordan T. Atherton

Electronic Thesis and Dissertation Repository

The Gambia, a country in West African, faces an increasingly daunting situation. They do not produce enough food needed to feed the population, yet population growth remains high, and the current area of land under cultivation is approaching total arable land available. Climate changes complicate matters further as the majority of farms lack irrigation and are dependent on rainfall to provide water to their crops. The purpose of this thesis is to provide the first 1st iteration of a system dynamics model that could be useful as a tool to assist decision in the Gambia better understand long-term implications of …

Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton

Department of Biological Systems Engineering: Dissertations and Theses

Soil carbon (C) is the largest terrestrial C pool globally, containing more C than the atmosphere and biosphere. Soil organic carbon (SOC) is a source and sink of CO₂ emissions to and from the atmosphere, thus influencing future climate change. Understanding SOC dynamics is also important for maintaining C stocks to sustain and improve crop yields. An existing model to estimate changes in SOC due to respiration was modified to operate in three computational platforms: MS Excel, MS Excel with Visual Basic for Applications, and supercomputing. This model was validated against CO₂ flux data from a 9-year field …

Water Demand And Allocation In The Mara River Basin, Kenya/Tanzania In The Face Of Land Use Dynamics And Climate Variability, Shimelis B. Dessu

FIU Electronic Theses and Dissertations

The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and …

Water Plans And Climate Change Plans In The Northeast And The Southwest, An Pham

Masters Theses 1911 - February 2014

To what degree are water managers in different regions in the United States thinking about and planning for climate change? To answer this question we reviewed water plans and climate change plans in all the cities with populations over 50,000 in the Northeastern and Southwestern regions of the United States. By locating and reviewing water and climate change plans in the described cities in the two regions, we found that of the 101 cities with over 50,000 people in the Northeast, 83 cities had water plans and/or climate change plans that could be found online; only 20 had plans that …

Assessing Climate Change Impacts On Water Balance, Runoff, And Water Quality At The Field Scale For Four Locations In The Heartland, Michael W. Van Liew, Song Feng, T. B. Pathak

Department of Biological Systems Engineering: Papers and Publications

This study employed the Soil and Water Assessment Tool (SWAT) to evaluate the impacts of projected future climate change scenarios on water balance, runoff, sediment, total nitrogen (N), and total phosphorus (P) at the field scale for four locations in the Heartland region: Sioux City (Iowa) and Columbus, Mullen, and Harrison (Nebraska). A conventional two-year corn-soybean rotation was assumed to be grown on each field. All fields were simulated identically in terms of topographic and cover/land management conditions. Model inputs for the fields differed in only

three ways: the forcing conditions for existing and future climatic scenarios (SRES A2, A1B, …