Effects of land use change and water reuse options on urban water cycle

The aim of this article was to study the effects of land use change and water reuse options on an urban water cycle. A water cycleanalysis was performed on the Goonja drainage basin, located in metropolitan Seoul, using the Aquacycle model. The chronologicale ects of urbanization were first assessed for the land uses of the Goonja drainage basin from 1975 to 2005, where the ratio ofimpervious areas ranged from 43% to 84%. Progressive urbanization was identified as leading to a decrease in evapotranspiration(29%), an increase in surface runo (41%) and a decrease in groundwater recharge (74%), indicating a serious distortion of the watercycle. From a subsequent analysis of the water reuse options, such as rainwater use and wastewater reuse, it is concluded that wastewaterreuse seemed to have an advantage over rainwater use for providing a consistent water supply throughout the year for a country likeKorea, where the rainy season is concentrated during the summer monsoon.