Spatial Changes in Urban Landuse and Ecosystems Arising due to Subway Network

Abstract

Rapid population growth and migration to the cities exert pressure on the urban land units as well as its encircling ecosystem land units. Since Japan has relatively less habitable area with mostly population is concentrated in major urban centers, urban and agricultural activities have to be conducted in a very small densely populated districts. In this study we have attempted to study the landuse changes caused due to the emergence of subway network within Sapporo city during the eighties as a part of urbanization process. Present study focusses along the 500 meters buffer zone of subway network within Sapparo city. ARC/INFO GIS was used for digitization and other data entry operations along the buffer zone. In some cases, some more areas in outer polygons were also considered in order to maintain the continuity along the buffer boundaries like river, marshes. The landuse maps of 1977 and 1993 prepared by Geographical Survey Institute, Japan were used as base thematic layers for analysis. Detailed urban landuses such as residential, commercial areas, industrial areas, Recreational areas etc. and also other ecosystem units such as agricultural/fallow lands, orchards and marshy areas were re-grouped and digitized. Then landuses were integrated to derive landuse changes. Using the INFO/TABLES database integrator within the ARC/INFO GIS environment, landuse statistics tables were generated for landuses in 1977 and 1993. Based on the change trends, break-up details for landuse conversion to commercial areas in 1993 were analysed and details are tabulated. The major findings are the conversion of agricultural fallow/marshy areas into other urban uses, including the conversion of marshy canal into an expressway.