Low-Carbon-Oriented Land Use Optimization In Mine-Agriculture-Urban Composited Zone

Land use change is one of the most important factors influencing global climate change and carbon circle.More and more researchers pay attention on how to reduce carbon emission from the perspective of land use.Taking the mine-urban-agriculture composited zone as example,the research focus on low-carbon land use in composited area based on remote sensing images and socio-economic statistic data,by the methods of remote sensing image interpretation,statistic analysis,and mathematic models.The purpose is to provide lessons and inspiration for low-carbon and sustainable development of resource-based cities.The main results are as follows.(1)The research revealed the process and machinsm of carbon circle in the mine-urban-agriculture composited zone.The process of the mine-urban-agriculture composited zone includes natural carbon process and factitious process.As to the calculation of carbon storage,the total carbon reserve decreased with 1.10%,as the result of the reduction of arable land and forest.The proportion of soil carbon storage was more than 93% all the time.The natural carbon storage reduced 0.12 million ton,while the factitious carbon storage increased 0.07 million ton.In the aspect of carbon flow,the gross vertical carbon inputs were 0.13 million ton,in which forest made the greatest contribution;the gross vertical carbon outputs(namely,carbon emission)increased,caused by increasingly intense human activities.The factitous carbon emission increased,in which producing activity made the greatest contribution.(2)The research analyzed the features of carbon flow caused by land use in the mine-urban-agriculture composited zone.The two ways to absorb carbon dioxide from the atmosphere are plant photosynthesis and water sequestration,and the total amount in each year was between 0.12 million ton and 0.15 million ton.The ways for carbon emission could be divided into natural ways and factitious ways,and the amount increased from 1.038 million ton in 1986 to 3.281 million ton in 2015,mainly caused by mining activity.Because of land use structure changes in 1986-2015,the total carbon sequestration increased 2.4 thousand ton,while the total carbon emission increased 224.4 thousand ton.Because of land use types transformation in 1986-2015,the total carbon flow was-177.4 thousand ton,in which forest transferred-in was the only way for carbon sequestration and mining land transferred-out was the main reason for carbon loss.The factors influencing carbon emission caused by land use were population increase,economic development,and mining activities.(3)The research proposed a low-carbon land use pattern suited to the mine-urban-agriculture composited zone.Multi-objective linear programming model was used to optimize land use structure,with land use types as decision variables,minimized carbon emission,maximized carbon storage,and maximized economic benefit as objective function,and low carbon emission type,high carbon storage type,and high economic benefit type as simulation senarios.By comparing the carbon emission,carbon storage and economic benefit of those three senarios,the high carbon storage type was believed as the best land use plan in the mine-urban-agriculture composited area,which can satisfy the demands from both low-carbon land use and economic development.(4)The research established a management system of low-carbon land use for the mine-urban-agriculture composited zone.The land use conflicts in the study area were caused by urban expansion,mining resource development,farmland protection,and villiage migration.The subjects in those conflicts were local government,coal enterprises,and urban and rural residents.Land use conflicts brought carbon emission via the increase of construction land and the transformation of land management approaches.The low-carbon land use management system included objects(macroscopic one and microcosmic one),subjects(local government,coal enterprises,and urban and rural residents),and supporting measures(institution system,department cooperation,science and technology support,and public participation).