| Summary: | The objectives of the research described in the thesis are the identification and
characterization of environmental issues associated with large infrastructure projects
which affect the project's economic performance, and the development of a
framework that will enable the analysis of the uncertainty in project economic
variables caused by such issues. The focus of the research is on the natural
environment.
The risk analysis framework is developed with the aim of enabling project
proponents and other stakeholders to identify, characterize and quantify environmental
risks during the project appraisal stage. The risk identification process is based on the
use of an extendable checklist or register of probable risks. This risk register acts as the
starting point of the identification process, as well as a knowledge base that can be
utilized on projects of a similar nature. The risks are categorized into 4 types based on
the effect of environmental issues on project work packages. The categorization allows
the selection of a suitable quantification method for the risks.
Monte Carlo simulation and influence diagrams are employed in developing the
quantification methods for the four risk types. Quantification of the economic
variables is carried out by considering them in terms of their decomposed primary
variables. Adjustment coefficients that represent the effect of external uncertainties are
utilized in quantifying the cost and duration uncertainty of work packages subject to
external uncertainty factors. Influence diagrams are used both to represent, and as an
aid to quantifying such external uncertainty factors. The Pearson family of frequency
curves is used to characterize the input distributions to the quantification process while
the rank correlations between the primary variables are evaluated by considering their
transformations into uniform variables on the unit interval [0,1]. A parameter of the
joint distribution between the transformed variables is used to assess the rank
correlation coefficient. The information elicitation process developed to obtain the
information required for the quantification process makes use of decomposition, the
use of directed questions, and appropriate feedback to elicit information of high
quality from experts.
The uncertainty associated with the economic variables is represented in a form
suitable for incorporation into the overall project decision making process. This final
output of the framework should help to enable the effective appraisal of the risks posed
by environmental issues to the economic performance of the project.
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