Research On Purple Line Delineation Based On Quantitative Evaluation Of Multiple Factors

The urban purple line is an original legal system for the protection of historical and cultural district and historic buildings in China,and the current delineation method of urban purple line has problems such as strong subjectivity,single and extensive delineation,inflexible management and excessive protection.Under the background of territorial planning and inventory planning,the delineation of urban purple lines needs to be based on comprehensive evaluation,taking into account the dual requirements of protection and renewal,and implementing flexible and refined management.This paper taking the ancient city of Jianchuan as the research object,first sorts out the historical development context of the ancient city of Jianchuan,and analyzes the characteristics of the ancient city.Secondly,with multi-source data,seven types of elements,including buildings,streets and corridors,which reflect the historical and cultural characteristics of Jianchuan Ancient City,were quantitatively evaluated from the two dimensions of "protection value" and "vulnerability".Finally,based on the comprehensive evaluation results,the multi-level purple line of Jianchuan Ancient City is delineated,and the multi-dimensional control purple line is delineated from different angles such as style and view.It is found that:(1)the ancient city and the new city of Jianchuan show the characteristics of integrated development,and the protection elements are mainly distributed linearly along the historical corridor,forming a ring structure centered on Jianyang Tower;(2)The vitality of the ancient city center of Jianchuan is low,the utilization of newly built service facilities is low and the ancient city is facing the contradiction between protection and renewal.Based on the qualitative and quantitative analysis of various elements of Jianchuan Ancient City,the multi-level urban purple line and multi-dimensional control line are finely delineated,and control measures are proposed,which can protect the cultural heritage and traditional style of Jianchuan Ancient City,while leaving space for the future renewal and development of the ancient city,and improve the vitality and sustainable development of the ancient city.