Research On Optimization Methods Of Low-carbon Land Use At The County Level

Climate change is one of the most pressing issues confronting humanity in the twenty-first century.Comprehensively controlling greenhouse gas emissions and seeking low-carbon development is the consensus of the international community.The county-level is of great importance in the implementation of China’s low-carbon development strategies,accounting for more than half of the country’s total carbon emissions,and their carbon emission intensity per unit of GDP is about 20% higher than the national average.Low-carbon land use is a key technology for spatial planning method to control carbon emissions.8%-30% carbon reduction benefits can be achieved by optimizing and adjusting the quantity structure and spatial layout of land use.Therefore,the establishment of a spatial planning carbon control mechanism based on low-carbon land use is of great significance to promote low-carbon development at the county level.Existing studies on carbon control in county-level planning are insufficient,the quantitative technology of low-carbon planning is weak,and the regulation mechanism and institutional system of low-carbon planning are not enough.Exploring the lowcarbon planning method at the county level is the key to solving the above problems.Low-carbon land use provides a good perspective.Thus,this study puts forward “how to improve the carbon control impact of spatial planning through land-use optimization at the county level towards low-carbon” as the key problem to be solved.According to the shortage of existing research,the key problem is further divided into three specific problems: Problem 1,the accounting method of land-use carbon emissions with clear geographical boundaries needs to be optimized;Problem 2,The mechanism of land use carbon effect lack systematically and dynamically consideration;Problem 3,Differential consideration and quantitative support for low-carbon land use optimization need to be improved.Given the above problems,this study first studied the theoretical basis of lowcarbon land-use optimization,clarified the research framework of low-carbon land use optimization at the county level,and then proposed “Accounting and AnalysisEvaluation and Forecast-Optimization and Adjustment” Low-carbon land use optimization method.Then establish multidisciplinary fusion and multi-modelintegration low-carbon land use planning methods as technical support,which include3 parts:(1)proposed the Point-Line-Area(P-L-A)carbon emission classified allocation method and localization coefficient method to measure the land-use carbon source and carbon sink;(2)established prediction and assessment method of land-use carbon effect based on STIRPAT-SD coupling model;(3)conducted low-carbon land use management method based on zoning classification and low-carbon multi-objective land use allocation(LC-MLUA)optimization model method based on the heuristic algorithm.Taking the typical county Changxing in Zhejiang as an example,the application and the verification of the methods is carried out.Finally,the carbon control mechanism of spatial planning is improved from the perspective of low-carbon land use.The results showed that:(1)Through in-depth analysis of the relationship between carbon emissions and land use at the county level and the mechanism of low-carbon land use optimization for carbon controlling,the method framework of low-carbon land use optimization at the county level is proposed by referring to the ideas of artificial intelligence to solve optimization problems.(2)Corresponding to the method framework,the land use carbon emission accounting method,land use carbon effect prediction method,and low-carbon land use optimization method are established as the technical support for the whole process,and the reliability and applicability of the method are verified by applied to the study area.(1)Vector land-use carbon emission/absorption map of Changxing County was drawn by using the land-use carbon source and sink accounting method,which contains 85,911 land patch carbon emission data and 41,609 land patch carbon absorption data.According to the maps,it was found that there were significant spatiotemporal differences in the carbon effect coefficients of various land use types,which can be summarized as four trends.5 key emission zones and 1 key carbon sink zone were identified.(2)The carbon effect coefficients of five types of land use were predicted by the STIRPAT-SD coupling model,and the carbon effect evaluation coefficient of all types of land use was calculated by a comprehensive multivariate method.Based on this,the carbon emission of the central urban planning scheme in Changxing County in 2035 was evaluated,and the key carbon control areas and land use types were identified.The total carbon emission of the planning scheme is obtained.(3)By using the zoning method of low-carbon land use,15 towns in Changxing county were divided into three levels of carbon control zones and four characteristic types to support the development of different carbon control strategies at the county level.The improved NSGA-II algorithm was used to solve the LC-MLUA optimization model in Changxing County,and 51 land-use optimization schemes were generated.According to the post-evaluation,the final decision scheme was obtained,which optimized 27.0%,6.2%,and 8.3% in terms of economic benefit,carbon emission reduction,and accessibility respectively.The paper provides concrete suggestions for the adjustment of land use structure and spatial layout in the central city.(3)The spatial planning and carbon control mechanism based on low-carbon land use is constructed,and three-level application scenarios of low-carbon land use optimization methods are proposed.The low-carbon planning system of “combination of planning and management” is improved,providing systematic path guidance and public policy guarantee for the formulation and implementation of low-carbon planning.This study has certain innovations:(1)Based on the in-depth analysis of the relationship between carbon emissions and land use at the county level and the mechanism of low-carbon land use optimization for carbon control,the framework of“Accounting and Analysis-Evaluation and Prediction-Optimization and Adjustment”for low-carbon land use optimization method at county level is proposed,which establishes a new paradigm for the county-level low-carbon planning from theory to technology;(2)Put forward P-L-A classified carbon emission allocation method and localization coefficient method for land use carbon accounting and draw the vector land use carbon emission/absorption map.The carbon emission measurement with land patches as the responsible subject is realized,which is the key to achieve the effect of carbon reduction through land use regulation;(3)The STIRPAT-SD coupling prediction model of land use carbon effect was established to systematically analyze the complex influencing mechanism of carbon effect of different types of land use,improve the accuracy of prediction of carbon effect coefficients of land use,and provide a parameter basis for planning carbon emission evaluation and optimization;(4)The low-carbon land use management control method based on zoning classification and the LC-MLUA model based on heuristic algorithm were constructed,which improved the multi-level low-carbon land use optimization,and provided quantitative decision basis for differentiated zoning control and urban land use optimization at the county level.