Spatial And Temporal Pattern Of Carbon Emissions From Land Use And Optimal Path For Carbon Reduction In Gansu Province

Climate change,as one of the global hot topics,is currently a major challenge for human society.Climate change will lead to problems such as the frequent occurrence of extreme weather and the continued degradation of the ecological environment in local areas on a global scale.Some studies have shown that carbon emissions caused by land use change have become the second largest source of greenhouse gas emissions after fossil fuel combustion.Land is the carrier of human activities,and land use is closely related to the layout of industrial structures and economic development and construction activities,and is expressed in the process of land use type transfer and structure adjustment.In the context of advocating low-carbon economic development,the focus of regional land resource management has become the optimization of low-carbon land use.This paper uses land use data of Gansu Province for the five periods of 2000,2005,2010,2015 and 2020 as the basis of research,analyses the temporal changes of land use in Gansu Province,adopts the direct and indirect carbon emission accounting method to measure land use carbon emissions and analyse carbon emission efficiency,and then uses GIS spatial analysis technology to summarise the temporal and spatial evolution of land use carbon emissions in Gansu Province from 2000 to 2020.The spatial analysis technique of GIS was then used to summarize the spatial and temporal evolution of land use carbon emissions in Gansu Province from 2000 to 2020.Secondly,based on the LMDI model,the influencing factors of land use carbon emissions in Gansu Province from 2000 to 2020 were identified and determined.On this basis,the Markov model and grey multi-objective model were used to predict the land use structure of Gansu Province in 2030 under the natural development scenario and the low carbon optimization scenario respectively,and the spatial patterns of land use under different scenarios were simulated with the help of the PLUS model,which provided a theoretical basis and a reference for decision making for land use carbon emission reduction in Gansu Province in 2030.The main conclusions of the study are as follows:(1)During the study period,land use carbon emissions in Gansu Province showed an increasing trend year by year,with carbon emissions increasing by nearly 1.77 times.The growth of carbon sources in Gansu Province is large and the growth of carbon sinks is small,with construction land being the main carbon emission and forest land being the main carbon sink.Carbon emissions from arable land decreased slightly,while carbon emissions from construction land continued to increase,and there is a strong correlation between carbon emissions from land use and construction land in Gansu Province;carbon sequestration from forest land,grassland and water increased,while carbon sequestration from unused land decreased.(2)From the perspective of carbon emission efficiency,the carbon emission intensity per unit of GDP in Gansu Province shows a gradual decline in general,while the carbon emission intensity per unit of land and per capita carbon emission intensity are increasing,but after 2010,the carbon emission efficiency of land use has changed significantly,the growth rate of carbon emission intensity per unit of land and per capita has slowed down,and the decreasing trend of carbon emission intensity per unit of GDP has slowed down;from the perspective of carbon emission spatial and temporal changes,the carbon emission of land use in Gansu Province shows an obvious temporal difference.From the perspective of regional carbon emission(absorption)changes,the growth of carbon emissions from arable land in Gansu Province is mainly concentrated in the west of the river,while carbon emissions from arable land in the south of Longdong Province are on a declining trend.The overall level of average carbon emission intensity in Gansu Province is relatively low.(3)The impact of land use carbon emission factors in Gansu Province during the study period is characterized as follows: land use carbon emission intensity,economic development level,land use structure and energy intensity are the factors contributing to the increase of land carbon emission in Gansu Province,among which the economic development level has the largest contribution value;land use area per unit of GDP and population size are the factors contributing to the decrease of land use carbon emission.(4)By predicting the quantitative structure of land use in Gansu Province through Markov model and grey multi-objective model,the carbon emissions of land use in Gansu Province in 2030 under different scenarios are estimated.Under the low-carbon scenario,the carbon sink land such as forest land,grassland and water area increases by0.97 million tons compared with the natural scenario;the carbon sources such as arable land and construction land decrease by 10.2923 million tons.Under the low-carbon scenario,the slowing trend of land area such as arable land and forest land is mitigated and the expansion rate of construction land is controlled,which indicates that under the low-carbon optimisation scenario,the growth of different land uses is more balanced and reasonable,and has a higher potential for carbon emission reduction.Using the PLUS model to simulate the spatial distribution of different scenarios in 2030,the low carbon scenario is able to better balance the contradiction between socio-economic development and carbon emission reduction in terms of spatial layout compared to the natural scenario.(5)Combining the spatial distribution of land use optimization and land use carbon emission characteristics under the natural scenario and the low carbon scenario,and at the same time drawing on Gansu Province’s territorial spatial planning,the regional carbon emission zoning and the main functions are combined to divide the province’s land use optimization into: high carbon emission reduction and optimization key development areas,low carbon emission control and efficiency coordination development areas,and carbon sink function enhancement key ecological areas.The optimization of land use spatial pattern should adhere to the guiding principles of lowcarbon development and ecological priority,scientifically and reasonably plan the land use structure,build a land use intensive low-carbon economic development model,and explore the path of urban and rural development in Gansu Province under a low-carbon economy.