Quantitative Description of Urban Landscape by Analyzing Topography in “Openness” Index A Case Study in Tokyo Yamanote Region

Although land use in megacity is changing rapidly, topography condition is relatively stable. To understand the characteristics of topography and its effect to the formation of urban landscape, it is important to discuss not only about natural environment sustainability, but also socio-cultural identity in the area. The topography of Tokyo is generally clarified as two zones, the west side called “Yamanote” which is the highland eroded by small rivers and valleys, and the east side called “Shitamachi” which is the alluvial land. There are some differences in urban landscape and socio-economical phenomena between these two areas which are influenced by topographical characteristics. Especially Yamanote area, labyrinthine street networks are formed by narrow and curved valleys, green spaces are preserved in steep land, while each place has unique landscape. Usually, these characteristics are discussed in fuzzy and qualitative sense, but in this paper, we present these characteristics by quantitative methods and indexes. We specifically analyzed such topographical characteristics in Tokyo Yamanote area by “Openness” index where slope can be described in broader scale. Furthermore, we described two characteristics of built environment by Space Syntax theory for street network pattern and GIS data for land use property included green area. By layering these three characteristics, the uniquely of areas could be identified. This method might be important to be applied in actual planning.