Stochastic approach for the analysis of demand induced transients in real water distribution systems

A stochastic approach for modelling and analysing the transients due to the users’ water consumptions in a real water distribution system is presented. The analysis is based on field measurements of water consumption at each user and pressure at three nodes, acquired at 1 min and 0.01 s time step, respectively. The hydraulic numerical model used is based on the Method of Characteristics and includes the unsteady friction. Several scenarios of water consumptions at 1-s time step are generated starting from those observed. The corresponding pressure variation scenarios are given by the numerical model and stochastically compared with the measured values. The analysis of the results shows that the approach is capable of stochastically reproduce the dynamic behaviour of the system. Specifically, the generated water consumption scenarios with random manoeuvring times allow properly reproducing the main statistics (mean, variance and minimum and maximum values) of the observed pressures. Finally, the average cumulative distribution of the simulated pressure viably simulates the cumulative distribution of the observed ones from a stochastic point of view.