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

Abstract

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.