Sensitivity Analysis of Yield Estimate of Urban Water Supply Systems

Abstract

Sensitivity analysis (SA) theory and techniques were used in this study to estimate the sensitivity of input variables on the yield estimate of an urban water supply system. The SA techniques considered were Morris method and Fourier amplitude sensitivity test (FAST), including the related extended FAST. A case study on a simple urban water supply system was conducted to assess the applicability and to study the limitations of these techniques and the SA framework adopted. Findings showed that the streamflow dominated all experiments, with the supply reliability threshold, the upper restriction rule curve and the consecutive months in restrictions threshold of subsequent importance. In a screening pass, importance ranking of the 26 considered variables from the Morris method were verified with FAST and extended FAST. Once minor errors were overcome by increasing the number of model simulations, a high resolution pass quantified the importance of the top 10 ranked variables. The case study also highlighted the need to improve the adopted SA framework by considering a different methodology considering different climate scenarios and alternative input variable handling strategies.

Key Words:

• Yield estimation
• Resource Allocation Model (REALM)
• sensitivity analysis
• Morris Method
• Fourier amplitude sensitivity test (FAST)
• extended Fourier amplitude sensitivity test (eFAST)

Additional information

Notes on contributors

D M King

Dr David King received his PhD in the hydrology and water resources from Victoria University in 2010. His main research interests are in water resources planning and management, including urban water cycle management, climate change impacts, water asset management and sensitivity analysis. David now works in the Water Information Services Branch at the Bureau of Meteorology.

B J C Perera

Professor BJ Chris Perera is the Associate Dean (Research and Research Training) in the Faculty of Health, Engineering and Science at Victoria University. He has worked in the broad field of Water Engineering (Hydrology and Water Resources) since he obtained his PhD from Monash University in 1985. His main research interests are in water resources planning and management, including climate change impacts, urban water cycle management, river water quality modelling management and water asset management. He has published over 100 refereed journal and conference articles. Chris provides training and technical support to REALM (a water supply planning and management computer package), which is widely used in Australia.