Two original computer simulation models are presented in this thesis. Although these models differ in their temporal, spatial, and structural dimensions, they are unified by a common purpose: to build quantitative understanding of environmental resources and better inform their future management. According to the U.S. Department of the Interior’s Minerals Management Service, there are significant undiscovered reserves of oil and natural gas located in the Gulf of Mexico Outer Continental Shelf region. While the existence of these energy resources is critical to the nation’s future economic well-being, of equal importance is the amount of already extracted energy that will be required to deliver the new fuel to society in a useful form; the difference between the two quantities is the net energy supply. “Energy return on investment” (EROI) is an indicator of the net productivity of an energy supply process; specifically, it is the ratio of gross energy production to total, direct plus indirect, energy cost. Chapter 1 describes a dynamic model designed to calculate the EROI of offshore energy extraction in the U.S. Gulf of Mexico from 1985 to 2004 under differing assumptions regarding energy cost and technology. In 2004, the EROI of the process is estimated to range from 10 to 25 depending on how comprehensively energy costs are defined. In comparison, the EROI of U.S. onshore petroleum extraction in the 1930s was at least 100. Ecosystem services are those functions of ecosystems that support, directly or indirectly, human welfare. Although interest in ecosystem services has surged in recent decades and is currently still on the rise, these phenomena have yet to be universally quantified. The current Multi-scale, Integrated Models of Ecosystem Services (MIMES) project is an ambitious attempt to do so through dynamic, spatially explicit modeling. As a part of this broad initiative, Chapter 2 details the development and testing of a model designed to measure and map the ecosystem service “water regulation” at multiple scales. The model is an extension of the well known and widely used “runoff curve number” method originally developed by the U.S. Department of Agriculture; it is applied to the Winooski watershed (Vermont, U.S.A.) and to the entire globe.
| Identifer | oai:union.ndltd.org:uvm.edu/oai:scholarworks.uvm.edu:graddis-1088 |
| Date | 11 July 2008 |
| Creators | Gately, Mark |
| Publisher | ScholarWorks @ UVM |
| Source Sets | University of Vermont |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Graduate College Dissertations and Theses |
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