A new integrated model system has been developed to examine this question: What are the relative effects of changes in land use and climate on the quantity and variability of river flows in relation to land use and water use management for sustainable development in a country such as Indonesia? This book describes the development of the integrated system and its implementation in Bandung basin, Indonesia. The model generates time dependent land use change patterns based on four policy-related land use change scenarios as well as time dependent climate scenarios based on IPCC SRES scenarios, and translate them into hydrological parameters for calculating the monthly discharge. The implementation results show that climate change has a greater possible impact on the change in the annual yield and monthly discharge variations and less impact on local scale discharge variation than the land use change. The superimposed effects of land use change and climate change can exacerbate the impacts, suggesting that land use management for sustainable development is very relevant. Professional in land use and water resources management and climate change adaptation will find this book useful.