Analysis of Drinking Water Delivery Patterns in the Northern Part of Stockholm – Effects of Population Growth, Holidays and Weather Conditions

Abstract: Global warming is widely reported to be a cause of water scarcity and increased water con-sumption. As a consequence, it becomes harder for water suppliers to be prepared for increaseddemands. It is possible to predict the upcoming demand with the help of machine learningtools, however, a preliminary analysis of water consumption patterns is important for a goodprediction. This work focuses on water consumption patterns and studies their change withtime as well as the effects of meteorological factors on it.In order to aid the investigation and scrutinization of the patterns, a new semi-automatedtool was developed. Its algorithm is based on the Mann-Whitney U statistical test and performsgrouping of the weeks with similar sets of hourly water consumption. It helps to frame off theseasons of the year within which the patterns are similar. Along with that, K-means clusteringwas applied to the data to retrieve the patterns and to compare the performance with the newlydeveloped algorithm. On top of that, the effects of the population growth and meteorologicalvariables on water consumption were studied.K-means clustering showed more robust performance than the newly developed algorithmand therefore the ways of improvement were discussed along with the significance of gooddata quality and thorough data pre-processing. It was detected that municipalities with thedifferent housing situation had different persistent summer patterns of water consumption. Ingeneral municipalities with prevailing individual housing tend to consume more water duringthe summer per capita than others. Furthermore, municipalities with prevailing individualhousing were observed to be less robust against temperature growth and humidity decreasethan those with prevailing apartment housing as the latter increase their water consumptionless significantly in response to mentioned meteorological variables change. Therefore, consid-ering the population growth, the benefits of planning new multi-apartment dwelling areas inpreference to individual housing were discussed in the context of sustainable water use andclimate change.