Assessment of Water Security in Indonesia Considering Future Trends in Land Use Change, and Climate Change

Abstract

Java Island as the heart of Indonesia economic and where 60% of Indonesian population live are facing serious water security. Existing average index of water use in Java Island has exceeded 100%. Both land use and climate change factors contribute further to the water security problems in Indonesia. But, there is lack of investigation on the relative contribution of both factors to the future water security in Indonesia. Knowledge on their relative contribution enables us to select the most appropriate mitigation or adaptation options. In this study we used SWAT hydrological model to investigate the relative contribution of both factors on a water quantity as one component of water security in Ciliwung watershed. Like all watersheds in Java Island, the Ciliwung watershed is experiencing rapid development of residential area which affect the water cycle in the watershed. Result of the SWAT simulation showed that the relative impact of a climate change on the future water security is more pronounced than the impact of land use change. This result is mostly consistent with another study with different typology of watershed in Sumatra Island where the land use change is dominated by rapid development of monoculture plantations instead of rapid development of residential area.