Applying the Rational Quantitative Optimal Risk Approach to Optimize Rehabilitation for a Portfolio of Dams

Applying the Rational Quantitative Optimal Risk Approach to Optimize Rehabilitation for a Portfolio of Dams

Author: G. C. Cloete, J. V. Retief, C. Viljoen
Conference: AFRICA 2017
Date: March 14-16, 2017

ABSTRACT
The Rational Quantitative Optimal (RQO) approach to risk based dam safety produces a definitive result for an assessment of the reduction of risk from the overtopping of embankment dams. The model is applied to 3 embankment dams in Namibia.

The model is based on principles of risk, but an assessment of a portfolio of dams provides discrete optimal results, not expressed in terms of probability. The model provides a transparent framework for decision making related to public safety, which will also appeal to the technically minded portfolio manager looking for a purely quantitative procedure.

The RQO approach relates the probability of occurrence of a flood, which exceeds the spillway capacity, to the cost of fractionally raising the non-overspill crest to accommodate the flood. By applying this relationship to a range of raised levels, the risk characteristics of a dam can be obtained as a technology curve. A portfolio of technology curves for several dams provides a tool for decision makers regarding priority and extent of rehabilitation.

 

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