Study On The Driving And Responding Relationship Between Land Use Change And Carbon Metabolism

Since limited urban land resources are responsible for more than 3/4 of global carbon emissions,a thorough analysis of the organic linkage between urban land use change and carbon metabolic system from the perspective of land use is an inevitable requirement for achieving the goal of low-carbon urban development.This study accounted for the carbon budget of various land use types as well as the horizontal"carbon flow"between land types based on the coupled"land-carbon"urban carbon metabolism system using six phases of land use data from 1995 to 2020 in the Hangzhou metropolitan area.Using the Markov-MOP and PLUS models,the study also simulated the optimal structure and spatial pattern of land use types under different scenarios in 2030 and then predicted the responsiveness of urban carbon budget in the future.The results showed that:(1)The land use change in Hangzhou metropolitan area was characterized by fragmentation,with rising land patch shape complexity and land use type diversity.(2)From 1995 to 2020,the carbon emissions of the study area increased from 12.94×10~8 tons to 49.79×10~8 tons,primarily due to rising carbon emissions of industrial land and other urban lands;the carbon sequestration decreased from 220.86×10~4 tons in 1995 to 218.88×10~4 tons in 2020,with forest land accounting for more than 95%of the total.High carbon emission patches were spatially clustered,while carbon sequestration patches were shrinking overall.Positive carbon flow was far less prevalent than negative carbon flow,and the dominant ecological relationship between land use types was exploitation/control.(3)The larger the proportion of construction land and the higher the degree of fragmentation,the greater the net carbon emission;the larger the proportion of arable land and the more regular the shape,the smaller the net carbon emission.The mechanism of construction land-driven urban carbon metabolism change was mainly influenced through other urban land structure and morphological changes.(4)The simulated results of land use structure in 2030showed a decreasing and increasing trend of economic benefits and ecological benefits under the baseline scenario,economic development scenario,and ecological protection scenario,respectively,reflecting three urban development patterns with different focuses.In addition,the carbon emission data were spatially distributed in the northeast-southwest direction,and the carbon sequestration data were distributed in the east-west direction.Based on this study,we proposed the policy path for optimal regulation of urban land use oriented to carbon metabolism,which were of great practical significance for achieving long-term balance and sustainable development of the urban carbon metabolism system.