Effect of uncertainty on water distribution system model design decisions

Derya Sumer, Kevin E Lansey

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

The goal of calibrating a water distribution model is to establish a numerical model that represents the real system. Given the uncertainty in field data, recent studies have examined model parameter and predictive uncertainties and how those uncertainties can guide future data collection experiments. However, a model is to be used in some decision making process and those decisions can be influenced by the model uncertainty. Therefore, a methodology is presented here to evaluate the impact of uncertainty in pipe roughness values on decisions that are made using the model for a system expansion design using a steady state hydraulic model. To complete the analysis, model parameter uncertainty is evaluated using a first order second moment (FOSM) analysis of uncertainty. Parameter uncertainties are then propagated to model prediction uncertainties through a second FOSM for a defined set of demand conditions. Finally, model prediction uncertainties are embedded in an optimal design model to assess the effect of the uncertainties on model-based decisions. If uncertainty levels are large, the monetary benefits of reducing uncertainties from additional data collection can be addressed directly by examining the change in the design cost with additional data. For demonstration, the methodology is applied to a small literature network. Results suggest that the cost reductions are related to the convergence of the mean parameter estimates and the reduction of parameter variances. The impact of each factor changes during the calibration process as the parameters become more precise and the design is modified. Identification of the cause of cost changes, however, is not always obvious.

Original languageEnglish (US)
Pages (from-to)38-47
Number of pages10
JournalJournal of Water Resources Planning and Management
Volume135
Issue number1
DOIs
StatePublished - 2009

Fingerprint

Water distribution systems
distribution system
system model
uncertainty
water
Uncertainty
water distribution system
decision
effect
methodology
prediction
Hydraulic models
cost reduction
cost
decision making process
model analysis
roughness
parameter
costs
Cost reduction

Keywords

  • Algorithms
  • Calibration
  • Design
  • Optimization
  • Uncertainty principles
  • Water distribution systems

ASJC Scopus subject areas

  • Water Science and Technology
  • Civil and Structural Engineering
  • Management, Monitoring, Policy and Law
  • Geography, Planning and Development

Cite this

Effect of uncertainty on water distribution system model design decisions. / Sumer, Derya; Lansey, Kevin E.

In: Journal of Water Resources Planning and Management, Vol. 135, No. 1, 2009, p. 38-47.

Research output: Contribution to journalArticle

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