Quantitative Research On The Compactness Of External Space In Existing Residential District From The Perspective Of Vitality

Under the background of shortage of urban resources,the living modes of modern residents are constantly changing,and the demand for space is surging in quantity and quality.How to provide efficient and perfect public services in the limited areas to create a high-quality and sustainable living environment becomes a new focus and challenge.The compact development mode provides the possibility for the coexistence of high efficiency and high quality of life,and becomes a strong support and inevitable choice for the upgrading of urban living environment.The population structure of the residential areas completed between 1980 and 2000 is aging and heterogeneity.The existing space environment is not complete with the residents’ demand,and the adjustment and updating of the residential area is the inevitable trend.Therefore,through the study of compactness of residential external space to improve the spatial quality on the basis of improving the efficiency of all aspects of the construction environment,so as to realize the excavation and recreation of the stock.It is an important way to improve the quality of living environment,increase the vitality of space and realize sustainable development.First,based on the study on space compactness of domestic and foreign,summarizes the achievements and shortcomings of existing research,and puts forward the quantitative research from the perspective of vitality.Secondly,it defines the connotation of "compactness of external space in existing residential district" and explores its influencing factors from two dimensions of objective space efficiency and subjective space quality.Space efficiency is studied from four perspectives: land utilization rate,function mixing degree,traffic accessibility and green space ecology.Spatial quality is studied from four aspects: safety,health,comfort and sustainability.Thirdly,taking 15 typical residential of tianjin from 1980 to 2000 as the research object,spatial data acquisition and SD evaluation of external space are conducted,and basic database is established.A series of quantitative methods such as correlation analysis,regression analysis of SPSS are used to screen and determine the influence factors.The index weight is determined by entropy method,and evaluation model is established.Finally,establish a space vitality model to analyze the correlation between compactness and vitality.then determine the reasonable threshold of the secondary index.Based on this,the compactness of the pilot residential area is analyzed,and the optimization strategy and reconstruction plan are put forward.Results show that vitality and compactness are positively correlated,it preliminary verifies by space efficiency and quality as the core to establish compactness assessment model is scientific and feasible.It expands the idea of quantitative study on the compactness,and provides basis for the environmental updating of the existing residential areas.