Objective. The present paper proposes a general compilation method of the interregional waste input-output table. As a case study of compilation, we estimated the interregional waste input-output table for Tokyo, which demonstrates the characteristic of waste emission and its treatment of Tokyo and other regions. We also indicate some critical issues and present some proposals, about the modeling of industrial waste treatment and the treatment of illegally-dumped waste in the interregional waste input-output analysis.
Results and Discussion. The compilation method of interregional waste input-output table consists of 4 steps, the estimation of the sectors of good and services, the waste input and output sectors, the environmental loads sectors, and the waste treatment sectors. The amount of waste and interregional transportation amount can be estimated by using the statistical data of local governments and Ministry of the Environment. The fourth step is the most important step. We present sub models to estimate the activity of waste treatment sectors by obtaining detailed information about waste treatment technologies from Tanaka and Matsuto et al. (Matsuto, 2005). The formulation of sub models depends on the characteristic of regions. We show a practical method of estimation and models in the case study of Tokyo. In the estimation of the interregional waste input-output table for Tokyo (TWIO), we assumed three types of sub models, which differ in the location and parameters of waste treatment facilities. The estimated TWIO table for 1995 demonstrates the characteristic of waste emission and its treatment of Tokyo and other regions. The sorts of waste of Tokyo are mainly composed of “Organic sludge”, “Construction debris”, “Inorganic sludge” and “Glass bottles and cullet”. Over 3 million tons of waste, which account for 12 %, emitted from Tokyo are transferred and treated in other regions. The tendency of the sorts of waste emission in Tokyo and in other regions is quite different. The sorts of waste of other regions are mainly composed of “Animal waste”, “Incineration ash”, “Molten slag” and “Inorganic sludge”.
Conclusions. The reliability of the interregional waste input-output analysis depends on the reliability of the compilation of its table. The sufficient disclosure and the quality of the related statistical data are the critical issues for the reliable compilation of the interregional waste input-output table. Especially the corroborative information for the modeling of the industrial waste treatment is needed. The improvement of the sub models for interregional waste transportation is also needed. The stock analysis of illegally accumulated dumped waste will also be an important subject.