Analysis on the Structure of Forests in the Metropolitan Areas

Abstract

This study analyzes the relationship between urbanization in the Tokyo metropolitan areas and the destruction of nearby forests. The factors contributing to urbanization and the destruction of forests are multi-dimensional, including the natural, economic, and social elements. A multivariate analysis was made on the structure of these factors, principal components were calculated, and the forces working to destroy forests in the respective areas were determined.In the metropolitan areas, farmland is appropriated as the first step in land use. Agricultural land lying adjacent to town areas are most readily urbanized, and flat ground can be developed easily. As a second step, following the use of farm land, forests are cut down for land use. The third step is large-scale appropriation and development of forests with a relatively low land cost, and the building of new town areas.Even with land cost rise, areas on a steep slope, forests on a steep slope or around temples and shrines are left untouched.Forests are the sole fort or defense line for preserving greenery in the metropolita areas. The avoidance of housing construction in areas with complex, irregular geographical features is aiding the conservation of forests. Purchasing forests with public funds in such areas is effective as well.It is appropriate to group forests (according to areas) and to consider measures and policies for preserving them in group units.Forests that still remain within urban areas ought to be purchased according to a specific plan, and must be secured as shelters or places for evacuation in times of disaster. Under present conditions, the Tokyo metropolitan area will become a district most vulnerable to the danger of various disasters.