Xi 'an Land Use Change Driven By "carbon Source" Space-time Evolution And Predict

Greenhouse gases such as carbon dioxide emissions caused global warming, a serious threat to human life and economic sustainable development, which had become an international issue to some governments. The study about carbon had become a hot research topic to many scholars. At present, the Xi’an city as the center of the biggest city in northwest China and the third international metropolis in our country, but the study about carbon emission to Xi’an is also very fewer. Taking Xi’an for example, based on regression model, the grey relational grade, IDW interpolation, Hopfield neural network, and LMDI method, RBF neural network, and grey model method, the paper analyzed the change of the carbon emission and the carbon sources pattern, and the paper also forecasted the carbon emission in the future. The results were as follows:(1)Significant differences of the change of the land use patternsThe data of land use were measured by the dynamic degree and the change of land use, results as follows:The dynamic degree of land use in districts of the Xi’an city from1997to2007showed:construction land> water>cultivated land> did not use the land> grassland> forest land. The construction land was the most one, the smallest one was the forest land.(2)Significant effects of the construction land to carbon emissionThe total carbon emission was increasing in Xi’an from1997to2007. Carbon emissions of the main land use pattern were different:construction land> cultivated land> forest land> grass land. The carbon emission of construction land was the most one. From the structure of construction land carbon emission to see, carbon emission of coal was the most one, which play an important role in the carbon emission of construction land.The correlation degree of different land use patterns with carbon emission was measured by the regression model and the grey relational grade. Results as follows: construction land> forest land> cultivated land> grass land. The main carbon source was construction land, and the correlation degree of construction land with carbon emission was far greater than that of forest land. So the carbon emission of energy consumption was larger than the carbon of forest land.(3)Spatial distribution of carbon sources in districts of Xi’an The paper measured the carbon source pattern based on the data of total carbon emissions of Xi’an city by IDW interpolation and ArcGIS in2007. Results as follows: Yanta District> Weiyang District> Baqiao District> Hu County> Chang’an District> Lianhu District> Gaoling County> Xincheng District> Beilin District> Beilin District> Lintong District> Liantian County> Yanliang District> Zhouzhi County. According to the structure and size of the carbon emissions, the land use pattern of Xi’an was divided into four categories.(4)The driving factor analysis of carbon emissionThe paper discussed the driving factors of the carbon emission’s change by LMDI method. From1997to2007, the energy structure, per GDP and population promoted the total carbon emission, and energy intensity instead. The main driving factors are economic development factor (per GDP and population) and the coal-dominant energy structure. The economic development factor was the primarily reason, and the immediate cause of the carbon emission was the coal-dominant energy structure.(5)The carbon emission in2015The total carbon emission of Xi’an would reach70.85477million t in2015by predicting through RBF neural network, grey model method and regression model. The main carbon source was still construction land, carbon emission would reach71.01787million t. At the same time, forest land was still the main carbon sink, carbon absorption would for284880t. But, the carbon emission of construction was far greater than the carbon absorption of forest land.