Morris method of sensitivity analysis applied to assess the importance of input variables on urban water supply yield – A case study

SummaryYield plays a central role in the processes, practices, management and operation of urban water supply systems. Improved accuracy of the yield estimate is important and can be obtained by improving knowledge of important variables. Yield is typically estimated via computational simulation using the entire sequence of available historic climate data. Sensitivity analysis provides a framework and many techniques that can identify important variables in a computational model. Using the Morris method, this paper investigates the importance of input variables used in the estimation of yield of urban water supply systems. The Barwon urban water supply system in Australia is used as the case study. Using a number of climate scenarios of various lengths, sensitivity analysis showed that the security criteria of the Barwon system was the most important to the yield estimate. The upper restriction rule curve also showed notable importance. Significantly the results showed that the use of a single climate sequence for estimating yield would produce misrepresentative results for another climate scenario.

► The Morris method of sensitivity analysis used on an urban water supply system.
► Twenty climate scenario of different streamflow and period were considered.
► System security criteria and restriction rule curves were most important.
► Importance of yield estimate input variables vary under alternate climate scenarios.
► A yield estimated under a single climate sequence may not suit alternative climate.