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.

Advances in Modeling and Management of Urban Water Networks

“…In the field of WDSs, all works are numerical analyses, though most of them, i.e., [38][39][40]43,44], present models calibrated on the basis of experimental data. The methodologies adopted are multi-faceted, ranging from physically based modelling, [40,41,44,45], to GIS algorithms, [42], data-driven techniques, [38,39,43], graph-theory, [43], and optimization algorithms, [38,41,45].…”

“…As for demand, Yousefi et al [39] propose simulation of urban water consumption in a Canadian city using chaos theory, with the aim to help optimize system management. As for the modelling, Mentes et al [40] show the extent to which a well-calibrated extended period simulation model can reproduce the hydraulics of real WDSs in Greece, while giving reliable insights into WDS management in emergency scenarios. The third explored topic lies in the exploitation of WDSs for energy recovery.…”

“…Mentes et al [40] develop an extended period simulation model for the WDSs of the Thessaloniki city in Greece to model the current operating state of the networks, as well as its response to emergency conditions resulting from failure in one of them. The model is calibrated under both normal and critical operating conditions.…”

Possible applications of GIS tools in order to prepare for drinking water distribution network emergencies

“…313-321) have been published and used as computer programs for a long time to calculate hydraulic parameters of interest, namely the headloss along pipes, flowrates and material transport with chemical reactions. It should also be noted that there is no standardised and legally obligatory methodologies for network hydraulic calculations, but an extensive number of different case studies are available in the literature (Ben-Daoud et al, 2020;Kourbasis et al, 2020;Mentes et al, 2020).…”

Hourly Variation Curve of Water Demand for Sectors of Ensenada, B.C.

“…of time with gene expression programming. Finally, Mentes, Galiatsatou, Spyrou, Samaras & Stournara, (2020) developed a hydraulic simulation model for the aqueducts of the city of Thessaloniki in Greece, where they obtained the hourly demand of the different areas that make up the system, using information such as from records of storage tank levels, from flow meters and from theoretically estimated data.…”