Study On The Correlation Between Spatial Morphology And Carbon Emissions Of Old Residential Areas In Cold Region

Over the past 40 years,the rapid urbanization process has improved the level of economic development and people’s living standards.However,the enormous impact of the urbanization process on China’s environment and energy has become an issue that cannot be ignored.The operational stage of urban residential buildings accounts for 38% of the total carbon emissions of the entire construction process,and this proportion is increasing.As a part of urban residential buildings,old residential communities have higher carbon emissions due to their outdated energy use and maintenance structure.Therefore,the low-carbon renovation of existing old residential communities has become an urgent issue.Previous research on carbon emissions from old residential communities has mostly focused on the energy use behavior,thermal parameters of the building envelope,and equipment and facilities at the individual building level,ignoring the huge potential of the block-level form of old residential communities for energy-saving and emission reduction.In this thesis,we combine Urban Building Energy Modeling(UBEM)method with the Rhino & Grasshopper parametric platform to construct a parameterized process for analyzing the carbon emissions of old residential communities during the operational stage,based on model construction-carbon emission simulation-statistical analysis.Using this process,we selected 60 typical old residential communities in Jinan,a cold region,and explored the correlation between the form of old residential communities and carbon emissions during the operational stage through means such as parametric simulation and statistical analysis.Based on the results of the statistical analysis,corresponding old residential community form updating strategies were proposed.This study can be divided into three parts: basic research,process construction,and quantitative analysis.Basic research: Firstly,we combed through the UBEM method for urban/block energy modeling,clarified the research on the correlation between urban form and carbon emissions,and analyzed the "carbon system" of old residential communities to define the boundaries of carbon emissions accounting during the operational stage of old residential communities.We then constructed a descriptive form factor index system for old residential communities and qualitatively explained its correlation with carbon emissions.Process construction: Based on the UBEM method and statistical analysis,a parameterized process was constructed for studying the correlation between the form of old residential communities and carbon emissions during the operational stage,and for proposing corresponding updating strategies.Quantitative analysis: According to the general process of the second part of the study,we selected 60 typical old residential community samples in the central city area of Jinan,a cold region,and established the geometric model of old residential communities combined with Arch Gis and Grasshopper.We used urban energy cluster simulation software UMI to simulate the carbon emissions per unit area of old residential communities by establishing typical nongeometric models of old residential communities based on investigation data.Using SPSS software,we analyzed the correlation between the form factor calculation data and the carbon emission simulation data by Pearson correlation analysis,and then constructed a regression model of form factor and carbon emissions using multiple linear regression.Based on the regression results,we extracted key influential parameters to study the carbon reduction threshold of key parameters using the control variable method.Finally,based on the results of the above quantitative analysis,we proposed a form-update strategy for old residential communities in cold regions that is oriented towards carbon reduction.The research results indicate that,for the cold region of Jinan,the plot ratio,building density,block enclosure ratio,form factor,and average street height-width ratio have a significant impact on the carbon emissions per unit area during the operation stage of old residential areas.And there are different degrees of influence on the four types of old residential areas,including panel,point,mixed,and enclosed types.Among them,plot ratio and block enclosure ratio are key parameters that affect the carbon emissions per unit area of old residential areas.The study found that for each increase of 0.05,0.07,0.05,and 0.13 in the plot ratio of slab-style,point-style,mixed-style,and enclosed-style neighborhoods,respectively,the carbon emissions decrease by1%.In terms of block enclosure,an increase of 0.07 in block enclosure leads to a 1% reduction in carbon emissions.Finally,based on the comprehensive quantitative analysis results,optimization strategies for the morphology of old neighborhoods in Jinan,a cold region,are proposed,which are supported by simulation studies.The research found that the application of morphology optimization strategies can reduce the per unit area carbon emissions of old neighborhoods by3.9%.