A transdisciplinary approach to oppressive cityscapes and the role of greenery as key factors in sustainable urban development

Through the recent process of urban development, characterized by urban expansion and redevelopment, industrialized countries have witnessed a surge in the number, scale and complexity of urban structures. However, it has become difficult to keep urban space adaptable to environmental realities and our cities don't completely meet the demands of society. These demands include the sustainable upgrading of social infrastructure and the regeneration of attractive urban space that is not only safe and highly efficient, but also consciously takes into account psychological influence. In this research "oppressive" refers to cityscape featuring high-rise buildings that cause negative psychological pressure on residents. Oppression is a barrier to achieving sustainable urban development and current research is a step towards addressing this barrier. This paper tries to bring the research of oppression to the international scientific society to present parts of years of Japanese research in this field. Through various methodologies researchers have proved that cities have oppressive and depressive affects on residents but the influencing factors are not completely measured. This research discusses the key parameters of psychological health by assessing the impact of trees effect on real urban oppressive environment. This paper also compares the largeness and quality of trees' affect against other physical factors in the city environment. Two experiments were conducted, one in the real Tokyo urban environment - as a mega city and the other utilizing 3-dimensional computer software to simulate the real urban environment in an experiment room. Totally, 60 participants from the field of architecture looked at specific images and responded by filling in a pre-designed questionnaire. Results indicate that oppression which increases as building's solid angle increases is significantly influenced by the existence of trees and the sky factor. The placement of trees or planting design in the urban area is important.