Calibration of EPANET Using Genetic Algorithm

Abstract

Hydraulic models are used widely to simulate the hydraulic performance of water distribution systems in both design and operational stages. These models have a significant role on decision making procedures. It should be noticed that the quality of model outputs are directly related to the quality of input data. However, because of several reasons such as change of pipes friction factors and diameter, nodal demands, etc., the output results are error prone. On the other hand the design’s criteria may be changed during operational period. Therefore, to improve the model performance and reduce the uncertainties during different consumptions procedures, it is necessary to calibrate these models. At the moment just a few commercial models such as WaterCAD which requires a considerable money expenditure are capable of calibration calculations (considering pipes friction factors or just nodal consumptions as the variable), besides the hydraulic analysis. In this research considering an optimization procedure using Genetic Algorithm, a computer code is prepared and linked to the hydraulic simulator (herein, EPANET) to calibrate the model. In this method some variables are considered: pipe friction factor (Hazen William Coefficient), nodal consumptions, combinations of both and pipe diameters. Finally to evaluate the advantages of the proposed methodology a test network is considered and the method is applied for different consumption scenarios.