Research On Units Identification And Characterisation-based Conservation Of Historic Urban Landscape

In the context of global habitat development orientation and the development stage of China,the demand for the continuity of urban culture and features is growing higher and higher.As the living places for urban residents and the fruit of culture accumulation,historic cities should receive more attention for local and social dimension values.At the same time,changing must be taken into consideration if urban heritage protection is to be taken to a higher level.However,compared to the deepening and maturing understanding of heritage,the protection zone method applied in China’s active heritage preservation system is still lagging: with an isolated dichotomy to divide the inner and outer of protection zones,which has made heritage,with temporal values,outside the protection zones neglected for a long time and also caused that the heritage resource inside the zones is facing the situation of passive waiting.This thesis introduces the concept of Historic Urban Landscape(HUL),which is increasingly advocated by UNESCO,and tries to turn the HUL concept into practical technical tools to solve the problem mentioned above of the lagging method to urban heritage preservation in China.Starting with the speculation of the concept of HUL,this thesis discusses the suitability of landscape characteristics as the supporting point of HUL’s transformation from concept to practice and then takes landscape characteristics as the core and starting point to build the supporting theoretical framework of HUL practical tools.HUL practical tools include the identification of HUL units as the cognitive tool of landscape characteristics and the proposed characterisation-based conservation of HUL based on cognition of landscape characteristics.The identification of HUL units is carried out in a progressive way from three dimensions including space,time,and perception.In the spatial dimension,this thesis systematically proposes a technical method of screening landscape characteristic elements,data collection and data standardization,then establishing a database based on Arc GIS platform.According to the clustering idea based on cell and unit,the spatial dimension elements are classified through the second-order clustering method in selforganizing classification,and the preliminary identification results of HUL units are obtained.In the time dimension,the landscape characteristic elements can be divided into synchronic layering and diachronic evolution,the information of multiple historical data is located,stored,and standardized by the method of map translation.The preliminary identification results of HUL units are enhanced by the method of expert-based classification with quantitative analysis.In the perception dimension,landscape characteristic in this dimension is represented by the shared value information,perception subjects are classified as residents and tourists,perception data is obtained by data mining from social media and minimum convex polygon analysis,then the shared value information is obtained by survey interview and natural semantic analysis,and finally,the "value-carrier" approach is used to identify the landscape characteristic elements of the perception dimension for each HUL unit,the improved identification result of HUL units is modified through public participatory-based classification.Ultimately,this thesis introuduces the characterisation-based conservation of HUL,based on the identification result of HUL units,and as a technical strategic path that integrates the management of change and its interface with current protection management system,using unit management as the primary path and further managing the change of HUL through two paths of active guidance and dynamic monitoring.From the perspective of continuing urban culture and characteristics,by developing the HUL practical tools,this research has improved the old method for protection zoning and discussed the strategies for continuing the essence of the zones based on the new method.This research provides new ideas for creating urban features in the context of a high-quality living environment and provides technical and methodological supports for the optimizing of urban conservation policies.