IMPACTS OF WEATHER VARIABLES ON URBAN WATER DEMAND AT MULTIPLE TEMPORAL SCALES

Population growth and urban development have contributed to increase in base urban water demand in a long-term temporal scale. However, if we consider a short-term temporal scale, weather variability is an important factor affecting daily, monthly and seasonal water demands. This study examines the relationship between urban water demand in the service area of the Metropolitan Waterworks Authority (MWA), Thailand, and two important weather variables: temperature and rainfall at various temporal scales. The growth of water demand was detrended and then normalized. The multiple linear regressions were used for analyzing the relationship. As a result, temperature has a strong significance to the demand that higher temperature causes higher demand, and the impacts are stronger for larger time scales. On the other hand, rainfall has a weak significance to the demand, but higher rainfall causes lower demand. Also, the impacts are more intense for larger time scales. As climate changes will affect both temperature and rainfall, MWA should consider the weather variability for a better management of water production and distribution.