Risk Prioritization of Buried Urban Water Pipelines Under Multi-Hazard Conditions: Reconstruction Index-Based Sustainable Infrastructure Management (RI-SIM)

Urban water distribution pipelines are critical for service continuity, public health and post-disaster recovery. However, municipalities often lack practical tools for prioritizing reconstruction under interacting natural hazards. This study applies the Reconstruction Index-Based Sustainable Infrastructure Management (RI-SIM) framework at street scale to prioritize buried water pipeline segments exposed to earthquake and flood hazards. A real pipeline corridor in Torbalı, İzmir, Turkey, was selected as the case study. Flood susceptibility along the pipeline corridor was assessed using the Height Above Nearest Drainage (HAND) method. Three-dimensional finite element analyses were then performed for representative pipeline layout configurations under earthquake-only and combined earthquake–flood-related scenarios to quantify structural response using maximum principal stress. RI-SIM integrated pipe diameter, material type, pipe age and failure history within the physical component (A1); seismic demand, HAND-based flood susceptibility and flood-related soil changes within the hazard–structural component (A2); and functional importance (A3). Component and sub-criterion weights were determined using the Analytic Hierarchy Process (AHP), and the resulting normalized component scores were integrated in a Geographic Information System environment. The main distribution pipeline showed the highest RI-SIM score of 0.931 and was classified as very high priority, followed by the secondary connection pipeline with a score of 0.789 and high priority, and the pumping/transmission line with a score of 0.633 and moderate priority. Under the combined earthquake–flood-related scenario, the side-by-side configuration exhibited the largest increase in maximum principal stress, from 141 kPa to 621 kPa, indicating a pronounced configuration-dependent response. The integrated framework, therefore, provides relative reconstruction priorities and complementary mechanical information for the investigated pipeline corridor under the defined multi-hazard scenarios.