Research On Land Use Change Carbon Emission Effect And Forecast

With the continuous improvement of social and economic level and the further acceleration of urbanization,global warming caused by massive greenhouse gas emissions has posed a great threat to the survival and development of mankind.Governments and scientists around the world have begun to pay attention to this focus problem.Glacier melting,sea level rise,biodiversity reduction,regional or global landslides,mudslides,El Nino and La Nina phenomena and other natural disasters brought by global warming have posed a great threat to energy,environmental,food and water security in the process of social development.Numerous studies have shown that there are two main ways to increase greenhouse gases:one is carbon emissions from fossil energy combustion;the other is greenhouse gases caused by changes in land use patterns and structures.Therefore,in the context of a low-carbon economy,it is particularly important to study the effects of regional land use carbon emissions and predict its future changes,to promote social and economic development and ecological civilization construction,and to realize land use planning and management of low-carbon emissions.This paper takes Changshou District of Chongqing as the research area.First of all,using remote sensing technology to obtain the landscape types image of Changshou District in2000、2006、2012 and 2018.Morever,the changes of land-use dynamic attitude and degree,and the factors affecting land-use change during the study period are analyzed respectively,and on this basis,the carbon emission effect and effect evaluation brought by the change of land-use types are studied.Last but not least,combined with the land use planning data of Changshou District,using carbon emission model and growth model to predict the net carbon emission of land use in Changshou District in 2020 has been done.According to the prediction results,the completion of carbon emission reduction in land use planning of Changshou District is tested,and providing the countermeasures and suggestions for future carbon emission reduction in land use.The results are as follows:(1)By means of interpreting TM/ETM4 remote sensing images of Changshou District in 2000,2006,2012 and 2018,and then classifying the interpreted results,six types of land use are obtained,namely cultivated land,forest land,grassland,construction land,water area and unused land.Using Kappa index to test the interpretation results,the accuracy of remote sensing interpretation is higher than 75%,which accord with the requirements of this study.(2)The change of land use in Changshou District from 2000 to 2018 is relatively obvious.In terms of land use area,arable land,water area and unused land show a decreasing trend,among which arable land decreasing most obviously.Forest land,grassland and construction land show an increasing trend,among which construction land has been in an increasing trend,while grassland area shows a trend of increasing first and then decreasing,and the overall increase area is much more than the decrease area.In terms of land use structure,the area proportion of various land use types in Changshou district has changed in various degree,but it has been dominated by cultivated land,forest land and construction land,among which the cultivated land area has been in a dominant position during the study period.(3)The conventional curve fitting method is used to fit and analyze the influencing factors of land use change and degree in Changshou District.The results show that population,urbanization rate,highway mileage,per capita GDP,per capita consumption expenditure and per capita garden green area have great influences on land use degree,and R~2>0.7 means they are highly fitting factor.There is a general correlation between forest coverage and industrial solid waste emissions and land use,and 0.3<R~2<0.7 means they are moderate fitting factor.Registered unemployed in cities and towns and the application amount of agricultural chemical fertilizer are low fitting factors,because of R~2<0.3.(4)Based on the revision of the land-use carbon emission model and relevant coefficients,the land-use carbon emission in Changshou District is calculated.The results show that the carbon emissions about land use in Changshou District between 2000 and 2018mainly come from cultivated land,construction land and water areas.In particular,energy resources consumed by construction land are the main source of carbon emissions.Carbon absorption mainly comes from forest land,grassland and unused land.There is the largest carbon absorption in forest land,accounting for 99%of the total carbon absorption.From2000 to 2018,There are two stages with the growth of net carbon emissions ahout land use in Changshou District,increasing first and then decreasing.However,the net carbon emissions from land use in Changshou District show an increasing trend in general.The growth trend of carbon emissions is basically consistent with the trend of net carbon emissions,and the trend of carbon sink has not changed much during the whole research period.(5)Using carbon emission model and growth model,combined with land use planning data and energy consumption data of Changshou District,the carbon emission of land use in Changshou District in 2020 is predicted.The results show that the carbon emission of land use in Changshou District in 2020 is 22865.00t.According to the land-use carbon emission reduction target of Changshou District in the 13th Five-Year Plan,the carbon emission reduction target of Changshou District in 2020 is verified.The results show that carbon emissions are needed to reduce by 1892.51t,and then it can achieve that goal of a cumulative decline in carbon dioxide and carbon emissions from the 10,000-yuan GDP by 2020.