Wavelet analysis of flow variations in a water distribution network
This study evaluates the relevance of wavelet analysis applied to water consumption in order to detect habits and changes in these habits. The demonstration is based on a series of one-hour flow observations from Quebec City’s water distribution flowmeter network for a 10-week period, which includes Christmas and the New Year holidays. Results confirm the non-stationarity of the flow data for all studied periods, which range from 2 to 256 h. The main cycle, which accounts for half of the natural variance of the series, has a period of 24 h, with a non-stationary intensity varying over 7 d, peaking on Sunday mornings and with lows during the work week. The second cycle, responsible for a third of the variance, has a period of 12 h, with an intensity which follows (although not as strongly as the previous cycle) a 7-d cycle, peaking during the week and with lows during the weekend. This behaviour differs during the Holidays, when most of the natural variance is explained by the 24-h component of the series.