Abstract
In this study, we constructed a simulation model to simulate for future water demand by different sectors (agriculture, industry, and domestic) in each prefecture of Japan. We also estimated the future water resource of each prefecture based on the data of AMeDAS, the GCM (Global Climate Model), and statistical literatures. The water demand model was constructed by using published statistical data and information derived from the geographical information system (GIS). The model can estimate water demand by different sectors from year 2000 to 2050 (the simulation time step is 5 years) for different socioeconomic scenarios and with the introduction of water-saving technologies. The water demand for different scenarios is estimated by considering changes in population, economic situation, area of cultivated land, population with access to a water supply, water recycling in industrial processes, among other factors. We finally evaluated the gap between the water demand and supply by each prefecture. An understanding of future water demand and supply using this model could help in a re-evaluation of appropriate water use, thus avoiding water shortages as well as allowing for an examination of the influence on river flows.
