Hydraulic Simulation and Analysis of an Urban Center’s Aqueducts Using Emergency Scenarios for Network Operation: The Case of Thessaloniki City in Greece

Abstract

The present work aims at developing a hydraulic simulation model for the aqueducts of Thessaloniki city in Greece to model the current operating state of the network, as well as its response to emergency conditions resulting from failure in one of them. Hydraulic simulations performed using WaterGEMS software in an extended period simulation (EPS) mode entail estimating water demand in all areas of the conurbation and calibrating the model under both normal and abnormal conditions. Calibration parameters set include the pipes’ roughness coefficients and head loss characteristics of throttle control valves (TCVs). Failure in the city’s aqueducts is confronted with the development and hydraulic simulation of five emergency scenarios of network operation, two of which consider possible interconnections of the studied aqueducts. These scenarios, which include appropriately defined intermittent water supply schedules for the aqueducts, are created on the basis of fair and equitable management of water among the different areas of the city, also assuming a small number of interventions/operations during the crisis. The simulations performed reveal quite a satisfactory compliance of the system’s operation with the defined schedules, and an improved management of limited water reserves in some areas of the network when considering interconnections of the city’s aqueducts.