Calibration of a model of an operational water distribution system containing pipes of different age

The aim of the paper is to demonstrate that the Levenberg–Marquardt algorithm can give successful results when operational water distribution systems are calibrated with the proper selection of parameter increment for the calculation of partial derivatives. The functional dependence of pipe roughness on age, which describes linear and nonlinear dependences, is proposed for the calibration of a model of a water distribution system containing pipes of different age. It is also shown that the visualization of response surface on a coarse grid is very useful for the analysis of the results.