Sunday, February 6, 2011

THE EFFECTS OF PROPOSED BRIDGES ON URBAN MACROFORM OF ISTANBUL: a syntactic evaluation

by Ayşe Sema Kubat, H. Serdar Kaya, Fırat Sarı, Gülşen Güler, and Özlem Özer

In recent years, the third bridge on Istanbul Bosporus has become a topic of lively debate but the probable results of introducing this new connection for the two sides of Istanbul are yet to be examined and evaluated. This paper investigates impacts of the existing and proposed bridges on the spatial development of the metropolitan area of Istanbul and explains the interaction between land use on urban macro form and transportation network via simulating the probable effects of the third bridge on the urban structure. The study has prepared and examined two syntactic maps that refer to two different time periods; the current situation and the future city network according to the proposed alternatives. The land use and urban growth data have also been collected for the two time periods available; before the two bridges were built and the current situation.
The study aims to estimate the possible effects of the new alternatives on land use, urban spread and location of Central Business District (CBD), by comparing the data of the earlier, current and future situations. According to syntactic analyses, it is clearly seen that the activities of CBD have expanded from the historical Eminönü district to the new CBD of 1980’s through Mecidiyeköy and Maslak axis, which also reflects the existing situation of CBD of Istanbul (Figure 5) (Kubat, 2001). The syntactic maps further show a shift of the central cores of Istanbul and a strong interaction between urban macro form and the existing and proposed bridges. This shift has been a potential threat for the northern sides of the metropolitan city, a vital region for the city as it has river basins and forest areas.
Space syntax have been built on the concept of pedestrian movement. This research, however, also investigates transportation system and traffic flow, which differs from pedestrian movement. The traditional ways to represent the urban network have some inefficiencies in making depictions about vehicular movement. Therefore, in order to represent the urban grid with priority given to the vehicular movement, a new deformed map of Istanbul has been prepared. Both the syntactic analyses and the analyses of deformed transportation network show the dominant character of highways and their effects on land use, and thus the possible direction of urban sprawl in Istanbul. 
In light of the two bridge experiences, and comparative analysis of urban macro form in various years from 1925 to 2005 using space syntax, this study will help to evaluate the likely effects of the proposed bridge alternatives on the urban development for sustainable future of Istanbul Metropolitan area. The study aims to be a source forurban planning in greater Istanbul and offer recommedations for today and future. The results of this study can also benefit other cities that deal with similiar problem of connecting two urban regions.


Mecidiyeköy , by portukcan
more about urban planning in Turkey:

Accessibility effect on urban land values

THE PLANNING HISTORY OF TURKEY: POLICIES, PRACTICES, BREAKDOWNS

Polycentric Urban Development and Istanbul

No comments:

Post a Comment