Evaluation Method Of Context Units In Ming City Of Xi'an

Under the background of deceleration and quality improvement,it helps historical towns better and more accurately identify and tap the potential value of the stock space to avoid the development tendency of the internal characteristics of the old city.Protect key issues conveyed by their value.Based on the existing research on the valuation of historical towns at home and abroad,this paper focuses on the issue of the relative lack of evaluation factors for historical information space relevance and historical space development process continuity in the current evaluation process of historical and cultural cities in China.Therefore,this article proposes to use the "Context Units"-the smallest spatial unit that carries the memory and value of a specific historical period and has relatively complete cultural information,as the object of historical town value evaluation.The purpose is to discover the regularity and characteristics of the context space of historical cities and towns,to establish the counter relationship between cultural information structure and urban space structure,in order to explore the value of historical town space itself in the process of formation and development of space context.Xi'an Ming City is the core and essence of Xi'an historical and cultural city.The old city area within the Ming City Wall area is the historical area with the most concentrated historical resources and the best value of the spatial pattern of the famous city.This article takes the Xi'an Ming City as the research scope,and explores the spatial organization and operating laws behind its context.First,based on context theory and spatial context-related theories,the concept,characteristics and value connotation of context units are established.Secondly,The historical evolution and characteristics of Xi'an urban spatial context elements since the establishment of a new city in the late Tang Dynasty were analyzed and analyzed,and the methods of condensing and expressing related information in related disciplines were used to analyze the context of different spatial levels in the Ming City of Xi'an The space unit is identified.Finally,the method of analytic hierarchy process and spatial data analysis is used to evaluate the value of context unit.Its main content includes the following three parts:1.Analysis of the Contextual Spatial Elements and Related Features of Ming City,Xi'an.The historical development stages of the Ming City of Xi'an are sorted out.The analysis focuses on the spatial elements of the context from the socio-economic structure and spatial evolution of the Xi'an Ming City at the end of the Tang Dynasty.Analysis of factors and patterns,and then a certain division of contextual context types,and research and judgement on the overall contextual space characteristics of Xi'an Ming City.2.The spatial unit identification and graph expression in Ming City,Xi'an.Introducing basic theories and methods such as biology,geography,and urban morphology,the planar pattern of the spatial unit of context in the Xi'an Ming City is discussed from three aspects: urban boundaries,land use patterns,and context-related clusters.From two aspects of morphological genes and relational genes,the genes of context space units were identified in Ming City in terms of overall and specific accuracy,and the unit types were divided to construct corresponding context space unit maps.3.Evaluation system and method construction of spatial context in Xi'an Ming City.Based on the phase characteristics of context space units,the comprehensive analytic hierarchy process gives index weights,and focuses on the evaluation of the value of context space unit types at the special level.Based on the establishment of the spatial context value system in Ming City.and the construction of its geospatial database of context information elements,it explores the distribution law of context spatial value in Xi'an Ming City.It is hoped to provide theoretical and practical references for the future protection and utilization of the context space of the Xi'an Ming City,and the value identification and protection of related historical towns.