Low-carbon-oriented Land Use Optimization Of Zhengzhou

Land is not only the natural carrier of land-ecosystem carbon source/sink, but spatial carrier ofthe social-economy system. Land use/cover change(LUCC) is one of the most significant factors those leadto global climate change. LUCC has deep influences upon the carbon circle at local and urban scale, rate、intnesity and direction of local circle precedure are subject to the land use mode、structures andintensity.Rational regulation to the land use change trends and adjust to the modes of land use can beessential methods to the increases of carbon source and decreases of carbon sink of land ecosystem.Based on the theory and method system of local land use carbon effect,this study conducts aresearch of low-carbon development of Zhengzhou City and analysis the carbon stock and flux on differentland use type, then based on the relationship between carbon stock, carbon flux and energy consumption,enbodies carbon incoming and outcoming on different land types. Three land use linear optimize modelswere constructed orienting maximum carbon stock, maximum carbon sink and minimum carbon emmision,by comparing patent of decreasing carbon emmission of these models the ultimate land structure schemewas confirmed.Finally, the land use structure optimization results were used for total control of land useareas, and basic farmland, ecological protection zone image layer were as spatial constraints, topography,soils, climate, transportation, land use and vegetation as driving factors of land use change, with thespatial distribution of land use of2009,using Logistic_AHP coupling model to determine the weights foreach factor, spatial land distribution of Zhengzhou in2020were simulated.(1) This paper constructs the urban land use carbon budget accounting system, based on which asystematic calculation and analysis of carbon input and carbon output of Zhengzhou were carried out,presenting a preliminary understanding of land use carbon stock, carbon input and carbon emissions status in Zhengzhou. The results showed that among the six land use types in Zhengzhou City, the carbon storageof farmland and construction land account for the largest share, respectively,36.7%and31.5%, followedby woodland, the proportion of the total carbon storage is20%, of which construction land the largestincrease in carbon stocks. In terms of carbon storage per unit area, woodland accounts for the most,2008to71.66t/hm2, followed by construction land, is49.29t/hm2. As for the inputs, the proportion of farmlandand woodland respectively account for54.17%and26.27%, followed by construction land, the proportionof the total carbon storage is16.5%. On the carbon input per unit area, the maximum is woodland, whichwas11.41t/hm2, followed by farmland, as5.14t/hm2. As far as carbon input per unit area of every landuse type, apart from construction land and farmland, carbon inputs throughout the rest of the types aremainly carried out calculations based on the density of carbon per unit area of soil and vegetation, so theannual variation is small. Land use carbon output of Zhengzhou was mainly from the construction land, forexample the carbon output of construction land in2008was60,189,700tons, accounting for98.8%of totalcarbon output of land use. Carbon output per unit area of construction land for was highest in2008whichreached346.67t/hm2. Carbon input of other types were mainly from vegetation and soil respiration, sointerannual variability is small.(2) On the basis of estimation of land use carbon stock and flux in Zhengzhou City, we carry outcarbon source/sink analysis of land use, respectively, and construct three objective functions withconstraints based on maximization of carbon storage, maximization of carbon sinks and minimize of carbonemissions in which the varibles were land use areas of different land use type of2020, the functions weresolved by linear programming software.Comparing with the carbon effect of land use planning ofZhengzhou results show that the carbon emissions minimize land use optimization schem can significantlyreduce the local carbon emissions, reducing the total amount of2,223,200tons of carbon emissions in2020 than the planning program, while on carbon storage and carbon sink, respectively, of more than2020planning11.46million tons and21,100tons. Thus, carbon emissions minimization scheme is much betterthan the other two schems.(3) Using minimize carbon emissions schem for total control, combined with the basic farmlandand ecological land and other space restrictive layer and on the basis of suitability assessment of land use,distribution with2009as the base year data,this paper uses GEOMOD model to conduct land use spatialoptimization simulation for low-carbon development in Zhengzhou City. Results were compared with landuse planning show that the optimized simulation schems can effectively inhibit the excessive growth ofcarbon emission in Zhengzhou, especially that of municipal districts, increase carbon sink of local area, andoptimize the land use spatial layout, and is instructive for low-carbon-oriented development of land use.