Sustainability Study of Sewerage Project Based on Future Estimated Population

Abstract

Recently, local government officials from various offices have been discussing methods to ensure the sustainability of Japan’s sewage system, which is threatened by the deterioration of river-basin sewerage, an aging population, and population decline. This study aims to analyze the sustainability of river-basin sewerage using micro estimated future population data. First, we developed polygon data for each treatment district of Japan’s river-basin sewerage, as there is currently no such open data. Second, micro estimated future population data for each building location were spatially joined to the polygon data, making it possible to analyze the sustainability of every treatment district based on future estimated population and the planned population for each sewage project. As a result, we can expect to maintain the future population of each treatment district in order to expand them appropriately. At the same time, it suggests that shrinking of the planned treatment district area is necessary to maintain river-basin sewerage depending on the future treatment district population. In order to promote further expansion and integration, it would be helpful to publish environmental data online including geospatial information in more detailed units than administrative areas as shown in this research.