This dissertation investigates the problem of uncertainty in complex ecological
models. The term "complex" is used to convey both the common and scientific
meanings. Increasingly, ecological models have become complex because they are
more complicated; ecological models are generally multi-variate and multi-leveled in
structure. Many ecological models are complex because they simulate the dynamics
of complex systems. As a result, and as science moves from the modern/normal to
postmodern/post-normal paradigm view of the world, the definition of uncertainty and
the problem of uncertainty estimation in models tread the lines between the technical
and the philosophical. With this in mind, I have chosen to examine uncertainty from
several perspectives and under the premise that the needs and goals of uncertainty
estimation, like ecological models themselves, are evolving. Each chapter represents
a specific treatment of uncertainty and introduces new methodologies to evaluate the
nature, source, and significance of model uncertainty. In the second chapter,
'Determining the significance of threshold values uncertainty in rule-based
classification models', I present a sensitivity analysis methodology to determine the
significance of uncertainty in spatially-explicit rule-based classification models. In the
third chapter, 'Process level sensitivity analysis for complex ecological models', I
present a sensitivity analysis methodology at the process level, to determine the
sensitivity of a model to variations in the processes it describes. In the fourth chapter,
'A Component Based Approach for the Development of Ecological Simulations',
investigate how the process of developing an ecological simulation can be advanced
by using component-based simulation frameworks. I conclude with reflection on the
future of modeling and studies of uncertainty. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31655 |
| Date | 19 December 2002 |
| Creators | Brugnach, Marcela |
| Contributors | Bolte, John, Bradshaw, Gay |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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