Seismic Resilience Assessment of Tehran's Southern Water Transmission Pipeline Using GIS-based Analyses

It is well accepted that an urban region's seismic resilience is directly related to the seismic resilience of the local water systems. Pipelines having low earthquake resistance generally include old pipes and those susceptible to corrosion. The seismic vulnerability of the water transmission pipelines can be evaluated along with the geologic hazards such as landslides, liquefaction, fault movement, etc. In this study, GIS-based analyses are implemented for one of Tehran's main water transmission pipelines, which transfer Mamloo Dam water to Tehran's southern regions, by considering the four most probable earthquake scenarios to evaluate post-earthquake serviceability of the studied pipeline. Transient Ground Deformation (TGD) due to seismic wave propagation, and also Permanent Ground Deformation (PGD), which may result in liquefaction (lateral spreading, and ground settlement) and landslide, are regarded as destructive earthquake effects on the water transmission pipelines. A restoration curve is also developed for the worst scenario to investigate the adequate post-earthquake water supply throughout the service area and ensure rapid system recovery. Results show that the water serviceability index regarding the worst earthquake scenario (Rey fault activated) is 28%, which means that more than 72% of the study area's population will experience severe disruption of water availability in a potential earthquake.