Calibration of Water Distribution Hydraulic Models Considering Different Decision Variables and Consumption Scenarios

In recent years, hydraulic models are widely used to simulate hydraulic performance of water distribution systems. They play a significant role in evaluation and operational management of these systems. Calibration is necessary for improvement of model function and reduction of the uncertainties during different consumption scenarios in the system. At the moment just a few commercial models are capable of calibration calculation besides the hydraulic performance evaluation. However, the popular and freely available model, EPANET can not be calibrated. In this paper, an optimization procedure is proposed using Genetic Algorithm (GA) for calibration of the hydraulic simulator. For this problem, the pipe roughness (Hazen Williams) coefficients, nodal demands and pipe diameters are considered as decision variables of the optimization problem. The procedure is implemented for four different consumption scenarios: normal, minimum, maximum and fire flow. Finally, to evaluate the proposed methodology, a test network at different consumption scenarios is calibrated and the results are compared. Comparison of the results shows that the best result with minimum error has been obtained when the fire consumption with considering both variables of Hazen-William coefficient and nodal demand was selected.