A Study On Net-Zero Carbon Oriented Urban Spatial Planning Strategies

Currently,the global climate crisis is becoming increasingly severe,and addressing climate change has become an international consensus.China has also proposed the goals of peaking carbon emissions and achieving carbon neutrality.As the main region for various greenhouse gas emissions,the decarbonization transformation of urban areas is of vital significance in addressing climate change.Constructing net-zero carbon cities is a comprehensive strategy for cities to cope with climate change.Unlike the gradual and vague requirements for carbon reduction in previous low-carbon cities,net-zero carbon cities point to deeper,systematic,and clear-cut carbon emission reduction changes in various urban sectors.Spatial planning is a powerful means for the systematic and coordinated construction of net-zero carbon cities.However,the current lack of research in measurement systems,mechanism studies,and implementation strategies hinders its potential.Therefore,research on spatial planning strategies based on net-zero carbon cities can effectively integrate net-zero carbon goals into spatial planning,promoting green and zero-carbon urban transformation.Based on a thorough review of domestic and international literature,this study systematically conducts research on spatial planning strategies for net-zero carbon cities from the perspectives of carbon sinks,carbon emissions,and comprehensive coordination.From the perspective of carbon sinks,this study addresses the inadequacies of existing urban natural carbon sink capacity measurement systems by incorporating the often-overlooked soil and natural carbon sink spaces within built-up areas into the measurement scope.Taking Hangzhou as an example,an urban natural carbon sink capacity measurement system is constructed,considering both carbon sequestration and storage capacities.The quantity,spatial pattern,and carbon neutrality contributions of urban natural carbon sequestration within the city’s scope are measured and analyzed.The results show that the carbon sink capacity of soil and small green spaces in built-up areas affects the measurement results in terms of quantity and spatial pattern.To ensure the reliability and feasibility of relevant spatial planning strategies,both should be included in the measurement system.In terms of carbon neutrality contributions,the role of urban natural carbon sequestration is necessary but limited,and must be combined with high-intensity carbon reduction strategies to achieve net-zero carbon goals.Based on the measurement and analysis results,this study proposes a series of spatial planning strategies aimed at enhancing natural carbon sequestration.From the perspective of carbon emissions,this study focuses on the public land in Hangzhou’s Shangcheng and Xiacheng districts,using machine learning methods such as the Boruta algorithm,random forest model,and Shapley Additive Explanations(SHAP)model to explore the relationship between urban public land carbon emission intensity and various spatial planning elements.The study finds that the floor area ratio is the key factor affecting the carbon emission intensity of urban public land.Some land use types,building density,and average building shape coefficient also have a certain impact on the carbon emission intensity of public land.Based on the analysis results,this study proposes spatial planning strategies for controlling carbon emissions from public land,including establishing a classification system for urban public land based on carbon control and a key planning indicator control system.From the perspective of comprehensive coordination,this study takes the Wangjiang detailed planning unit in Hangzhou’s Shangcheng District as an example and constructs a net-zero carbon-oriented urban multi-objective land use optimization allocation model based on a vector data model,considering both spatial and nonspatial objectives.After solving the model using the second generation Nondominated Sorting Genetic Algorithm(NSGA-II),this study employed the Technique for Order of Preference by Similarity to Ideal Solution(TOPSIS)to select the comprehensive optimal land use scheme from the feasible solution set.The results show that for detailed planning units in urban central areas,the vector data structure,land use classification considering floor area ratio,and the inclusion of spatial objectives represented by land use compactness contribute to the scientific and feasible land use schemes generated by the model,providing a reference for net-zero carbon urban spatial planning.Moreover,by analyzing the optimal land use schemes generated under different scenarios,it is found that the proportion of urban green spaces and commercial and public facilities with different floor area ratios has a critical impact on net carbon emissions and economic benefits of land use schemes.Based on the land use allocation results,this study proposes spatial planning strategies for the detailed planning units in urban central areas,such as rational layout of urban green spaces and coordinated control of high floor area ratio commercial and public facilities land area.Constructing net-zero carbon cities is a systematic and comprehensive project.The comprehensive and integrated research perspective of this study helps to avoid a one-sided and superficial understanding of urban net-zero carbon goals.The results of this study are expected to help urban planners and decision-makers gain a more profound understanding of the relationship between spatial planning and carbon emissions and sequestration,construct a scientifically rational carbon reduction logic,and propose more scientifically effective net-zero carbon urban spatial planning strategies.