To validate the mathematical model of a water distribution network is necessary to minimize the deviation between the calculated values and those measured on the real system. For existing networks the calibrating procedure must consider as parameters both the hydraulic resistance elements and the node consumptions.
In general, the number of field measurements available is insufficient to recognize exactly each individual parameter of the system. Furthermore, to enlarge the range of validity of the model it is convenient to carry out measurements of pressure and flow rate under different operating conditions. Therefore a properly mathematical technique is suitable to reduce the discrepancies.
Our experience shows that a satisfactory adjustment of the model’s parameters in that sense requires a previous calibration by zones. We have used optimization techniques without derivatives for the first stage and non deterministic methods based on sensitivity analysis for the second one, with very good results.