Seismic resilience evaluation of water distribution systems considering hydraulic and water quality performance

Abstract

The resilience evaluation of infrastructures provides an essential basis for resilience enhancement and disaster mitigation in urban communities. This study presents a seismic resilience evaluation framework of water distribution systems (WDSs) that integrates hydraulic with water quality simulation. The seismic damage scenarios of WDSs are generated according to the seismic fragility model of pipelines and Monte Carlo simulation, and the post-earthquake recovery of pipeline damages is simulated by a dynamic importance-based recovery sequence. The negative influence of earthquake hazards on water quality is investigated by the reduction of chlorine concentration in water, which depends on the changes in water age and supply path caused by pipeline damages. The water quality performance of WDSs is measured by the residual chlorine concentration at user nodes, and two water quality performance indexes, namely, the water supply that meets the quality threshold requirements and the water supply without quality deterioration after the earthquake. The proposed framework is implemented in three benchmark WDSs with different layouts and operational features. Application results show that the water quality resilience of WDSs tends to be lower than that of hydraulic services, and the relative difference in system resilience loss between the water quality and hydraulic service performance ranges from 17% to 286%, which varied according to the layout of WDSs. The water source redundancy, and not the loop pattern of the pipeline network, has crucial impacts on the water quality resilience of WDSs after an earthquake event.