Temperature and rainfall thresholds for base use urban water demand modelling

This paper shows how anew daily demand model incorporating base use values calculated using temperature and rainfall thresholds for East Doncaster, Victoria, Australia was evaluated. The model is based on a postulate that total water use is made up of base use and seasonal use, where base use represents mainly indoor use and is independent of climatic effects such as rainfall and temperature and seasonal use on seasonal, climatic and persistence components. Using the daily data collected for East Doncaster, Victoria, Australia water supply distribution zone and the corresponding rainfall and temperature data from 1990 to 2000 reference or threshold levels in which water use is independent of temperature and rainfall were identified. The base values were correlated with the day of the week and climatic factors such as temperature and rainfall. Results revealed these base values to be climate independent but are affected by weekends and weekdays. The calculated base use values using temperature and rainfall thresholds were incorporated in a total water demand model and showed strong correlation with R-2 of 71%. The model is further validated using an independent set of data from 2000 to 2001 and yielded an R-2 of 83%.