The applicability of robustness measures to water resources decision making

The choice among alternative water supply sources is generally based on the fundamental objective of cost minimisation. There is, however, a need to consider sustainability, the environment and social implications in regional water resources planning, in addition to economics. In order to achieve this, multi-criteria decision analysis (MCDA) techniques can be used. There are a large number of MCDA methods, however, none of them can be considered as appropriate for all decision-making situations. Selection of the most suitable method can therefore be difficult. Various sources of uncertainty exist in the application of MCDA methods including the definition of criteria weights and the assignment of criteria performance values. Robustness / sensitivity analysis can be used to analyse the effects of these uncertainties and in this paper, two existing methods are applied to two water resources case studies. The results indicate that consideration of the various sources of uncertainty should be an integral part of the decision-making process. However, the existing methods could be improved by enabling concurrent alteration of the subjective input values and the method should also be applicable to a range of MCDA techniques.