Proposal of resilience indices for water mains subject to hydraulic transients and case study in Franca (Brazil)

ABSTRACT Water main bursts not only lead to financial losses, but also water losses. Climate change and water resources scarcity puts in perspective the need to understand the conditions of the water transportation infrastructure to prevent accidents. The objective of this work is to present resilience indices related to the operation of the water system and infrastructure operational limits to aid decision maker to evaluate risk. The resilience indexes were established based on four indexes arising from transient flows simulation: burst pressure, minimum transient pressure, maximum air volume and resultant forces. Decision making on a complex problem with many parameters based on a simple index is not straightforward, therefore we used a multicriteria decision technique to assist, the simplified three-scale Analytic Hierarchy Process (AHP). To test the proposed method, a case study of a trunk main from the municipality of Franca, Brazil is presented. To calculate the indexes a hydraulic model with transient flows of the referred system was simulated. For the case study, a few scenarios were evaluated. The scenario where no protection devices are present is the most critical.