Study On Carbon Footprint Assessment And Low-carbon Strategies Of Urban Settlements In China

Urban settlements are the main mode of urban residential buildings, energy conservation and emission reduction for urban settlements is an important field of construction industry to address climate change and achieve low-carbon development. Caculation method of the carbon emissions is an important prerequisite for energy conservation, low-carbon development of urban settlements; at the same time, researches about urban settlements Low-Carbon Assessment, Low-Carbon Techniques, and Low-Carbon Cost-Effectiveness have become the key factors of successful implementation of low-carbon development of urban settlements.The characteristics of urban settlements and its carbon emissions were analyzed and the research purpose and principles of urban settlements carbon footprint were also determined; urban settlement’s life cycle was divided into planning & design, materials & equipment production, construction, operation & maintenance and disposal five phases, and the system boundary of carbon footprint analysis about the settlements in different stages of the life cycle has been exlicited; Within the system boundary on main carbon unit process were analyzed, followed by the analysis of carbon emissions inventory for all stages, in order to determine the level of unit process carbon emission activity and to build the carbon footprint calculation models for each phase of the ueban settlements life cycle.According to the characteristics of the carbon footprint of urban settlements, proposed low-carbon evaluation principles of urban settlements and build a low-carbon evaluation system, including design, construction and operation, three-phase dynamic evaluation models; from the phases of life cycle and major carbon source, carbon sink systems,the two perspective views, selected urban settlements lifecycle carbon index, construction low-carbon index, operation low-carbon index, energy using low-carbon index and water using carbon index etc., evaluation elements in different levels, to build the appropriate evaluation criteria; and proposed corresponding low-carbon rating methods based on the selected evaluation factors and evaluation criteria.Through in-depth studying of the operation mechanism of low-carbon urban usettlements, from the two dimensions of lifecycle phases and function systems of urban settlements, low-carbon technologies related to urban settlements in accordance with the building, equipment systems and the built environment were divided into three categories. Based on this classification system, the dissertation focused on the analysis of these low-carbon technologies which have great influence to the energy conservation and emission reduction of urban settlements, and their potential emission reduction abilities. Thus, proposed a two-dimensional and three-category low-carbon technology system of urban settlements.According to the cost-effectiveness characteristics of urban settlements, in the perspectives of economic, environmental and social, an approach of incremental cost and incremental effectiveness for analyzing the low-carbon cost-effectiveness of urban settlements was proposed to build cost-effectiveness analysis model; through analyzing cost-effectiveness of main low-carbon techniques of building, equipment system and environmental aspects, the appropriate options for low-carbon technologies were determined; considering the influence factors of incremental costs and incremental effectiveness of low-carbon technologies, and the total investment, utilizing methods of 0-1 programming and multi-objective planning to establish the low-carbon technology options optimization model of urban settlements lifecycle, to achieve selecting best options of low-carbon technique system in urban settlement life cycle in the different targets of needs within different priorities.A certain urban settlement was selected as the case study, based on the previous research results, the carbon footprint of this settlement was analyzed, low-carbon index was rated, major low-carbon techniques were analyzed and the corresponding carbon emissions strategies were proposed. The results show that the analysis of carbon emissions calculation, low-carbon assessment, and low-carbon techniques of this case study is fair good to support and verify the theoretical achievements of this research.