Research On The Effect Of Land Use Carbon Emissions In Rapid Urbanization Area

The urbanization process in China develops rapidly,rapid urbanization has become the new normal,improving the carrying capacity of the land non-agricultural industries,and the construction land is overspreading.In the process of urbanization,land use change is regarded as a key factor which affects carbon emissions.Under the influence of non-agricultural land,carbon emission effect cannot be ignored.Therefore,to clarify the coupling relationship between land use and carbon emissions,calculate carbon emission effects of land use and forecast carbon emissions effects of land use at end of the 13 th Five-Year Plan,has practical guiding significance to regulate the land use carbon reduction and efficiency increase.Based on the background above,this paper takes rapid urbanization area Jiangsu province as a case study and constructs research pattern of “macro research – micro research” collaborative exploration from provincial,regional and municipal level.Using the method of combination of economic measurement and spatial analysis,this paper reveals the temporal and spatial characteristics of land use change,the calculation of land use carbon emission effect,the contribution of decompose impact factors to carbon emissions,and forecasts land use carbon effect in 2020.The major conclusions of this paper are as follows:(1)From the point of spatial and temporal characteristics of land use change,the construction land expansion in Jiangsu Province in 2001~2014 was too fast,the consumption of cultivated land resource was accelerated,and the forest and grass land and water area were impaired seriously.In terms of growth rate of construction land in three major areas,the order is as follow: Southern Jiangsu(4.001%)> Jiangsu(3.36%)> Middle Jiangsu(3.05%)> Northern Jiangsu(3.03%).It is noteworthy that forest land area in the rapid urbanization areas-Northern Jiangsu and Middle Jiangsu were reduced,while it showed a slight growth in Southern Jiangsu,where has completed the rapid urbanization.During 1996 and 2015,the speed of construction land expansion in Xuzhou and Nanjing showed an increasing trend,and cultivated land showed a trend of increasing consumption.During 1996 and 2015,the overall landscape fragmentation decreased,the patch shape tends to be irregular.(2)In terms of the calculation of land use carbon emission,(1)From the provincial level,the carbon effect manifests as carbon emission in Jiangsu from 2001 to 2014,and the carbon emission had increased from 5.955×107t to 2.2549×108t,with 98.16% of the carbon source came from the construction land.The transfer orbit migrated toward rapid urbanization areas – northern Jiangsu and middle Jiangsu after 2007.(2)From the regional level,the transfer orbits and features of three large regions in Jiangsu are different,and there was a positive correlation between land carbon emission and economic development.The carbon emission intensities of Southern,Middle and Northern Jiangsu were 49.74t/hm2· a(southern Jiangsu),12.84 t/hm2·a(middle Jiangsu)and 10.27t/hm2·a(northern Jiangsu)respectively,and the construction land took up 99.39%,97.04% and 95.58%.(3)From municipal level,carbon emissions of Xuzhou and Nanjing increased by 3.656×107t and 3.93×107t.Among them,the change of land use carbon emissions of carbon increased land use were 3.862×107t and 4.34×107t.The change of land use carbon emissions of carbon reduced land use were-2.068×106t and-4.09×106t.The carbon emissions caused by the change of cultivated land to construction land were the most in both cities.The maintained carbon emissions in 2015 was 3.229×105t and 1.03×105t.(3)From the aspect of land use and carbon emission factors decomposition,from 2001 to 2014,economic level was the main driving forces of land use carbon emissions,which led to the increase of carbon emissions of 2.74×108t,1.413×108t,4.058×107t and 7.006×107t in Jiangsu province,southern Jiangsu,middle Jiangsu and northern Jiangsu.Energy intensity was the main inhibitory factor to the growth of carbon emissions in Jiangsu province and three regions,which led to the reduction of carbon emissions of 1.2787×108t,6.799×107t,2.143×107t and 2.822×107t.Population size and the energy structure had a weak positive effect on land use carbon emissions in Jiangsu Province,which the cumulative effects were accounted for only 6.57% and 5.3% of comprehensive effects.There were differences in carbon emissions between the energy structure and population size of the three major regions.It is worth noting that the population size played an important role of promoting the carbon emissions in Southern Jiangsu.(4)On the prediction of land use carbon emissions in 2020,(1)CA-Markov model has a better effect on land use prediction.From 2015 to 2020,construction land in Xuzhou and Nanjing keep rising.The phenomenon of construction land occupying cultivated land will be still serious.In Xuzhou and Nanjing,92% and 85.8% of the occupied land of construction land will come from cultivated land.The variation of cultivated land and construction land continues to increase,and there is an aggravating trend in Xuzhou while slowing trend in Nanjing.The negative rate of change of forest land,bare land and water area in Xuzhou also will aggravate.(2)During the 13 th FiveYear Plan period,the intensity of carbon emission in Xuzhou shows positive growth and in Nanjing there is negative growth.(3)As for the prediction of carbon effects,from 2015 to 2020,carbon emission of land use will increase by 3.287×107t and 1.198×107t in Xuzhou and Nanjing.The effect of carbon increased will be much larger than the effect of carbon reduced,and the amount of latter only accounts for 2.9% and 10.9% of the former in Xuzhou and Nanjing.