Temporal And Spatial Differentiation Of Land Use Carbon Effect And Low-Carbon Optimization Simulation In Chaohu Lake Basin

Land use change is one of the main sources of CO₂ emissions.It is crucial to clarify the carbon effect of land use,reasonably adjust land use types,and optimize land use structure to enhance carbon storage and control carbon emissions.Therefore,this thesis uses five Landsat images of the Chaohu Lake Basin in 2001,2006,2011,2016,and 2021,and combines qualitative and quantitative analysis to study land use change,spatiotemporal differentiation of land use carbon effects,and optimal simulation of land use low-carbon in Chaohu Lake Basin,and proposes suggestions for low-carbon sustainable development.The main research achievements and conclusions are as follows:（1）The characteristics of land use change in Chaohu Lake basin were revealed.Based on the five phases of remote sensing images,combined with SVM supervised classification and visual interpretation,the land use classification map for the five phases was obtained,and the study was divided into six one-class types and ten second-class types,including cultivated land（paddy field,dry land）,forest land,grassland,water area,construction land（towns,villages,mining and transportation land）,and other land;From 2001 to 2021,paddy field in cultivated land was the most important type of land use in Chaohu Lake basin,accounting for about 60%of the total area,followed by forest land,construction land,and water areas.The relatively obvious change in land use structure was that the area of cultivated land decreased year by year,and the construction land increased year by year;In terms of spatial changes,paddy fields have been transferred violently,covering the entire research area,and are always the largest land type transferred in and out,the largest source of transfer is village land,and the transfer out of towns,transportation and other construction land mainly appears around towns;The forest land has significantly increased,mainly appearing near the original forest land,as well as within urban areas such as Hefei City and Jin’an District of Lu’an City.（2）The spatiotemporal differentiation of land use carbon effects in Chaohu Lake Basin was clarified.Based on the land use classification data of the fifth phase,the carbon storage and carbon emissions of different land use types were obtained using the In VEST model,direct emission coefficient method,and indirect estimation method.The land type with the richest carbon reserves is paddy field in cultivated land,with a significant increase in carbon emissions from land use.Construction land is the largest source of carbon emissions.Forest land has a strong carbon absorption capacity;From 2001 to 2021,the carbon reserves in Chaohu Lake Basin first decreased and then increased,and the carbon emissions continued to increase,but the growth rate gradually decreased.The carbon absorption change was small,and the carbon emission intensity per unit of GDP significantly decreased,from 1.88 Ton/ten thousand yuan to 0.29 Ton/ten thousand yuan.The carbon emission intensity per unit of land and construction land increased year by year,but the growth rate slowed down and tended to be stable;The carbon storage in Chaohu Lake Basin presents a spatial pattern of low in the central part and high in the southwest,east,and south,corresponding to land use types and vegetation distribution.The increase in carbon emissions is mainly distributed around urban built-up areas such as Hefei City and Jin’an District,Lu’an City.（3）Simulated the low carbon optimization of land use in Chaohu Lake basin.Using multi objective linear programming,constraints centered on total land use,economic and social development,and ecological and environmental protection were established.With economic and social development,ecological and environmental protection,and low carbon as benefit objectives,the results of land use structure optimization and benefit profiles under three scenarios were obtained.Among them,carbon emissions in the low carbon scenario under ecological protection constraints were significantly reduced,and economic,ecological,and low carbon benefits were developed in a balanced manner.According to the actual situation,combined with the overall land space planning of various cities and counties,based on the 2021 land use classification data and the quantity demand of different land use types under the low-carbon scenario,the driving factors were selected and the PLUS model was used to simulate the low-carbon spatial layout of land use in the study area in 2026.The cultivated land increased slightly,with an increase of 0.18%,widely distributed in the study area,and the forest land increased 3.8%,distributed around the original forest land,The construction land decreased by 117.94 km2,and the expansion was significantly controlled.Compared to 2021,carbon reserves increased by 0.82%,carbon emissions decreased by 9.38%,and the economy maintained a growth rate of over 5%,achieving low-carbon sustainable development.There are 25 figures,35 tables,and 123 references in this thesis.