Research On The Prediction Method Of Urban Construction Land Carbon Emissions From The Perspective Of Built Environment

Urban construction land is not only the space carrier of our life,work and rest,but also the main carrier of carbon emissions.According to statistics,about 80%of the global carbon emissions occur in urban construction land,so it is of great significance to reduce urban construction land carbon emissions for coping with global warming.Built environment is one of the important factors affecting urban construction land carbon emissions.How to reduce urban construction land carbon emissions through the optimization and adjustment of built environment based on low carbon goal is a frontier scientific issue in the current urban and rural planning discipline.Therefore,the paper takes the central urban area of Changxing County as the research area and different types of construction land plots as the research object,and proposes the analysis framework of the prediction method of urban construction land carbon emissions from the perspective of built environment.Using GIS,statistical analysis method,machine learning and other methods,the paper studies the construction method of carbon emission database of urban construction land based on Arc GIS,analyzes the relationship between built environment and urban construction land carbon emissions,and establishes a BP neural network prediction method of urban construction land carbon emissions based on built environment.By further defining the planning application scenarios of the method,the paper can accurately predict urban construction land carbon emissions level under different built environment scenarios in the spatial planning preparation stage,and evaluate the carbon reduction benefits achieved by different low carbon optimization strategies of built environment.Firstly,the paper establishes the analysis framework of the prediction method of urban construction land carbon emissions from the perspective of built environment.By defining the concept connotation of urban construction land carbon emissions,building energy consumption and built environment,the paper defines the research connotation of urban construction land carbon emissions based on building energy consumption,and built environment factors that affect urban construction land carbon emissions,including density factor,function factor and form factor,with a total of 11 built environment factors.On this basis,the paper analyzes the interaction between built environment and urban construction land carbon emissions,and concludes that density,function and form of built environment have an impact on building energy consumption mainly from the energy consumption demand of urban construction land,microclimate environment,building noumenon characteristics,and energy consumption activity content and intensity of building users,thus affecting urban construction land carbon emissions and indirectly reacting to built environment.Secondly,the paper puts forward the construction method of carbon emission database of urban construction land based on Arc GIS.Taking the central urban area of Changxing County in Zhejiang Province as an example,and through field investigation and conference interview survey,the paper obtains the annual electricity consumption,building,land use,enterprise and population data of different types of construction land in 2018.Then based on Arc GIS 10.2 system,the paper through the overall structure design,data information input,urban construction land carbon emissions and built environment factors measurement three steps,and constructs the carbon emission database of urban construction land.Specifically,it includes 293 different functions of urban construction land carbon emissions sample data selected by stratified random sampling,and 933 different functions of urban construction land built environment data.Based on the database,on one hand,urban managers can query the spatial location and attribute information of carbon emissions data and built environment data on different functions of urban construction land.On other hand,urban managers can also conduct spatial analysis on the values of urban construction land carbon emissions and built environment.Thirdly,based on the statistical analysis method,the relationship between built environment and urban construction land carbon emissions is quantitatively analyzed.The conclusions are as follows:（1）The residential land carbon emissions is significantly correlated with 11 built environment factors,including building area,building density,population density,land use,land mixing degree,land construction time,land area,building floors,building shape coefficient,building aspect ratio,and building orientation at the level of 0.01 or 0.05 respectively.The industrial storage land carbon emissions is significantly correlated with 4 built environment factors,including building area,industry category,land area,and building floors at the level of 0.01 or0.05 respectively.The public land carbon emissions is significantly correlated with 7built environment factors,including building area,population density,land use,land construction time,land area,building floors,and building shape coefficient at the level of 0.01 or 0.05 respectively.Among the density factors,there is a positive unitary linear trend line relationship between building area and residential land carbon emissions,industrial storage land carbon emissions and public land carbon emissions.The relationship between building density and residential land carbon emissions shows an inverted"U-shaped"quadratic polynomial trend line,and when building density is 0.22,the residential land carbon emissions is the largest.The relationship between population density and residential land carbon emissions presents an inverted"U"type quadratic polynomial trend line relationship,while it presents a positive"U"type quadratic polynomial trend line relationship with public land carbon emissions.When the population density is 6634 people/km2,the residential land carbon emissions is the highest,and when the population density is 5884 people/km2,the public land carbon emissions is the lowest.Among the function factors,the mean value of different functions of urban construction land carbon emissions are significantly different.There is an S-shaped change trend of increasing,decreasing and increasing between the land mixing degree and residential land carbon emissions.The relationship between land construction time and residential land carbon emissions presents an inverted u-shaped quadratic polynomial trend line,and the relationship between land construction time and public land carbon emissions presents a positive unary linear relationship.There is a positive unitary linear trend line relationship between land area and residential land carbon emissions,industrial storage land carbon emissions and public land carbon emissions.Among the form factors,there is an inverted"U"-shaped quadratic polynomial trend line relation between building floors and residential land carbon emissions,and when the building floors is 10,the residential land carbon emissions is the largest.There is a negative linear relationship with industrial storage land carbon emissions and a positive linear relationship with public land carbon emissions.There is a negative linear relationship between building shape coefficient and residential land carbon emissions and public land carbon emissions.There are positive and negative linear regression relationships between building aspect ratio,building orientation and residential land carbon emissions respectively.Fourthly,based on MATLAB platform,the paper establishes a BP neural network prediction method of urban construction land carbon emissions based on built environment.After comparison and verification,the error rate between the predicted value and the real value of the overall residential land carbon emissions is 12.65%,in which the error rate between the predicted value and the true value of 1-3 floors urban residential land carbon emission,4-6 floors urban residential land carbon emission,and≥7 floors urban residential land carbon emissions is 11.72%,11.38%and 14.84%,respectively.The error rate between the predicted value and the real value of industrial storage land carbon emissions is 13.80%,and the error rate between the predicted value and the real value of high carbon emissions industrial storage land,medium carbon emissions industrial storage land and low carbon emissions industrial storage land is17.94%,13.68%and 9.77%,respectively.The error rate between the predicted value and the real value of the total public land carbon emissions is 15.73%,in which the error rate between the predicted value and the real value of the commercial land carbon emissions,medical land carbon emissions,commercial land carbon emissions,school land carbon emissions,and administrative office land carbon emissions is 7.45%,14.22%,19.68%,18.10%and 19.21%,respectively.Based on the prediction results,conclusions are drawn as follows:（1）There are significant differences between the average of different functions of urban construction land carbon emissions and carbon emissions intensity per unit land area,which shows the increasing trend of village residential land,public welfare public land,urban residential land,commercial public land and industrial storage land.（2）There is a significant positive spatial correlation of urban construction land carbon emissions,and the spatial correlation of urban construction land carbon emissions gradually weakens with the increase of distance.（3）By delimiting the carbon emission intensity zoning,it is helpful for planning management departments to put forward targeted low-carbon planning strategies.Finally,the paper puts forward the idea and process of planning application of urban construction land carbon emissions prediction method,and takes the control planning and urban design scheme of Taihu new town in Changxing County as an example to carry out planning application research.The conclusions are as follows:（1）The overall carbon emissions of the planning scheme before optimization is 217488409.70 kg CO₂.（2）From the point of reducing the carbon emissions of the planning scheme,this paper determines 24 low-carbon optimization methods of built environment factors.（3）After optimization,he overall carbon emissions of the planning scheme is 183547901.80kg CO₂.（4）By comparing the carbon emissions of the planning scheme before and after optimization,the total carbon reduction of the planning scheme after optimization is33940507.90kg CO₂,accounting for 15.61%of the carbon emissions of the planning scheme before optimization.It shows that the optimization and adjustment of the built environment factors in the planning scheme can effectively reduce the carbon emissions of the planning scheme,and provide more scientific guidance for the quantitative simulation of space planning and the formulation of carbon reduction strategies under the guidance of low-carbon.The main innovations of this paper are as follows:（1）Taking building energy consumption as the entry point,this paper proposes a research perspective of more detailed calculation and analysis of carbon emissions differences on different functions of construction land plots within cities and towns.（2）From three aspects of density,function and form,this paper puts forward the built environment factors that affect the urban construction land carbon emissions,and further reveals the comprehensive mechanism and quantitative relationship between built environment and urban construction land carbon emissions.（3）BP neural network is applied to establish the prediction method of urban construction land carbon emissions based on built environment.By proposing the specific path of the urban construction land carbon emissions prediction method in planning practice to play a role in carbon reduction,and the planning application scenario of the method is further clarified.