Assessment of Hydraulic Resilience and Return Time of Sadra City Water Distribution Network under Earthquake

Assessing the resilience of the urban water distribution system against natural disasters and unforeseen events is very important in urban management. In this paper, the amount of hydraulic resilience of Sadra water network against earthquake has been studied. Various strategies have also been defined for repairing the water distribution network. In this paper, Sadra city water network is first simulated in EPANET and then imported as input into WNTR (Water Network Tool for Resilience) code, which is programmed in Python. WNTR is developed based on the theory of complex networks and calculates the index of citizens' access to water services. In this paper, 18 scenarios were examined considering changes in earthquake intensity, earthquake center and two repair strategies with a decrease in the amount of consumer demand. Pipes are divided into two categories, general and minor damage, based on the probability of failure. Todini index is used to evaluate the failure criteria in the water distribution network. Results showed that while the increase in earthquake intensity in all areas is positively correlated with the paternal damage of the water supply network, the return time of the network to normal conditions depends on the repair strategy and change in the expected consumer demand. Meanwhile, the fractal analysis of the water supply network has been performed in order to analyze the redundancy of the network based on the fractal dimension in order to find the most vulnerable area of ​​the network. Assessing the hydraulic resilience indices and fractal analysis depicted that the North is the most vulnerable area and South has the highest network resilience. Finally, the return time of the system to normal condition in each scenario and the number, ID and location of damaged pipes in each scenario was determined.