Study On Uncertainty Optimization Model Of Low Carbon Reduction In Urban Agglomeration

Urban agglomeration of Changsha-Zhuzhou-Xiangtan (CZT) was selected as the case study area in this study based on the country’s "12th five-year control scheme for greenhouse gas emissions," and a low carbon reduction optimization model applied in the CZT urban agglomeration was established by chance constrained programming (CCP) method in order to achieve the goal of the lowest carbon emissions during the planning period in the CZT urban agglomeration with the constraint conditions of industrial value-added, energy consumption per unit GDP, cost, industry carbon emissions, carbon sink area, etc. In order to provide wider decision space to decision-makers, an interval chance constrained programming (ICCP) optimal model for low carbon reduction was also established. Further, a low carbon reduction optimization model was also established by two-stage stochastic programming (TSP) method to satisfy both the emission reduction plan of greenhouse gas and the minimum reduction cost of greenhouse gas emission in the CZT urban agglomeration.The established optimization models were applied to optimal the carbon reduction in the area of CZT urban agglomeration. The optimal results of CCP model demonstrated that the optimized carbon emissions are 31.34 million tons,31.09 million tons, and 30.89 million tons in the CZT urban agglomeration with different carbon sequestration land areas of the three kinds of probability of default level 0.01,0.05,0.1. It was calculated that the carbon emissions optimized by CCP method reduced 23.22%,23.83%, and 24.32% comparing to the original program planning carbon emission (40.82 million tons) in the 2015. Besides, the optimal results of ICCP model showed that the optimized carbon emissions are [3096.21,3171.32] ten thousand tons, [3071.74,3145.67] ten thousand tons, and [3050.96,3126.61] ten thousand tons in the CZT urban agglomeration with different carbon sequestration land areas of the three kinds of probability of default level 0.01,0.05,0.1. It was found that the carbon emissions optimized by ICCP method reduced [22.30,24.14]%, [22.92,24.74]%, and [23.39,25.24]% comparing to the original program planning carbon emission in the 2015. Further, the optimal results of TSP model showed that the optimized costs of carbon emission reduction are 926.85 million yuan,870.39 million yuan, and 806.62 million yuan in the CZT urban agglomeration with different kinds of probability levels of low, medium, and high. It was found that the carbon emission reduction cost optimized by TSP method reduced 21.63%,26.38%, and 31.78% comparing to the original program planning carbon emission reduction cost in the 2015. On the other hand, the decision-making solutions optimized by TSP model satisfied both the obligatory targets of "12th five-year control scheme for greenhouse gas emissions" and "12th five-year" development plan of CZT urban agglomeration in Hunan Province", and they also can planning the area of carbon sequestration land area in the planning area. The optimal results can help to reasonable control the carbon sink area, effectively reduce the carbon emissions in the city, and full develop the unused land, solve the problems of rapid urbanization development and land waste, reasonable and effective use of land resources, and finally achieve the optimal economic goals.