Moving from single values to trade-off curves for assessing the performance of water resources systems under uncertainty

Water resources management under uncertainty is made difficult by the subjective judgements that have to be made using current methods. This paper addresses this issue by introducing a method that eliminates the need to pre-select performance values of water resources systems from a distribution based on risk appetite. Instead, the entire trade-off curve between risk appetite and performance is considered. This enables more informed decision-making, as it will identify whether (i) a solution is always better/worse than another, irrespective of risk appetite, thereby removing any subjectivity or doubt from the decision-making process, or (ii) a solution performs better than another for some risk appetite levels but worse for others, enabling a more informed solution choice based on full knowledge of the nature of the trade-off between risk appetite and performance. The utility of the proposed approach is confirmed via a case study of a reservoir system in China.