NGWA Event and Education Recordings Archive

Hydrogeological Decision Analysis Revisited

In the early 1990s, a team of researchers at the University of British Columbia, of which the speaker was a part, published a series of papers in Ground Water that proposed an increased use of decision analysis for engineering design projects in which the hydrogeological environment plays an important role. The framework that was presented there involved the coupling of three distinct tools: a stochastic simulation model for groundwater flow and transport, a Bayesian treatment of the uncertainty that exists in the hydrogeological parameter fields, and an economic decision model based on a risk-cost-benefit objective function. As in most decision-analysis studies of that era, it was assumed that decisions would be made by a rational, financially-driven decision-maker, who might be risk-averse, but who would otherwise make decisions that maximized his or her economic position. This approach did not address the controversies, that were emerging even then, between conventional economists and a new breed of behavioral economists who question the purported rationality of traditional economic theory. The behaviorists hold that decisions are strongly influenced by the psychological profile of the decision–maker: their values and belief systems, emotional states, political leanings, career ambitions, ethical standards, and moral principles. It is their opinion that the traditional decision-analysis framework offers much sleight-of-hand and many opportunities for bias, sufficiently so that defining risk often becomes nothing more than an exercise in political power. Hydrogeologists need to be aware of the complexity of the decision process, the close relationship that exists between our technical input and the risk term in a decision analysis, and the widely-differing views toward the methodology and value of risk calculations. Watching these arcane matters unfold can sometimes lead to frustration and disillusion on the part of the technical team, but a healthier attitude is one that recognizes the non-technical complexities as providing a richer, more-interesting, and more-challenging milieu in which to carry out our technical work.