The efficiency of visual buffer zone to preserve historical open spaces in Iran

Abstract

Neglecting visual consideration in determining regulations related to height and skyline in urban plans in the area around historical sites has caused irreparable damages to authenticity of historical open spaces. Despite all existing agreements and regulations related to cultural heritage, there is a significant gap between regulations and what is implemented in the real world. It is even more challenging in the context of dynamic and heterogeneous metropolitan cities with historical backgrounds. So, the present study was conducted to develop an effective and applicable 3D-model for visual buffer conservation and height regulation in development of urban planning in the area beyond approved regulations of historical sites; with an emphasis in two historical sites in Iran, that is, “Zandieh Complex”, and “Hafezieh Tomb” in Shiraz with a high risk of making scratched skyline. In this study, it was attempted to decompose existing approaches to visual analysis techniques and then providing a technical yet simple enough platform for city decision-makers to be used for defining visual buffer zones with height regulations. The research method is a combination of quantitative (to build 3D evaluation model) and qualitative (to compare and to build a framework) methods. Firstly, range of visual effects was quantified by employing “three-dimensional visual surfaces” using Shiraz municipality data bank and DEM topographic data. Secondly, a comparative analysis was conducted to test correspondence between results and authorized map of “the Cultural Heritage Organization” and “Municipality’s comprehensive plan of Shiraz”. Results of the study suggested that the use of this applicable model can increase public attention to visual and intangible value of historical open spaces. The model will also present a less prone to errors and integrated height managing tool to bring authorities of conflicting interests into transparent conservation. Using suggested methodology will make height pre-assessment faster with minimal cost and expertise.