The purpose of this study is to extend the policy alternatives of water resource planning by assuming the regional industrial water demand is derived by the final consumption of goods. Use of goods or services derives the water demand not only from the industry which process and complete them but also from the industries which produce the inputs such as materials, capital goods, energy, etc.. The sum of those derived water demand per unit amount or price of final goods or services is defined as water intensity. The water intensity of goods is affected by both of the water use of each industry and the production technology or industrial relation. The water demand is redefined as the product of water intensity and the amount of final goods which is consumed by household. From the viewpoint of the water intensity of goods, the import of goods imputes the industrial water demand to the other region and relaxes the water resource limitation of the region itself. On the contrary, the export of goods increases regional water demand.
In this paper, firstly the water intensity of goods is formulated based on the input-output model. Secondly inter-regional dependence of water demand is formulated using the inter-regional trading pattern coefficient. Some numerical results are presented based on the national and regional input-output tables and the OD table of freight transportation. For example, the private consumption by the residents of Chiba prefecture derived 136 liter of water per day per capita on average from Ibaragi prefecture in 1980.
