Study On Urban Building Material Stock And Carbon Emission Oriented To Sustainable Management

With the continuous progress of urbanization,the urban built environment not only accumulates massive amounts of resources,but also generates a large amount of solid waste,resulting in a series of environmental problems such as land resource occupation and air quality deterioration,which is the main“hot spot”of construction materials and energy consumption in cities.To effectively monitor and manage the resources using and waste processing of building system,realize the urban sustainable development,the purpose of this study is to analyze the material stock and flow of the urban building system,to describe urban building system physical spatio-temporal distribution pattern,to reveal the rule of material metabolism in building system,to explore the evolution path of building system in new and old urban area,to identify the drivers of changes in building material stock,to estimate building material impact on the environment.Finally,suggestions on urban resources and environment management and urban sustainable development are put forward.Based on satellite remote sensing images in 2003,2010 and 2017,combined with4D-GIS model and material stock method,this study compiled the building material stock database of Lixia District,Jinan,and analyzed the distribution pattern and evolution law of material stock and flow of the urban building system.Based on the driving force analysis equation,the driving factors behind the change of building material stock are explored.And based on literature research and combined with the carbon emission factor method,the carbon emission model of unit area of building life cycle was established to estimate the status of carbon emission generated by materials in the building system of Lixia District of Jinan.Then,scenario analysis method was adopted to explore the influence of different scenarios on carbon emissions of building system materials,and to find ways to reduce carbon emissions of building system.The research results show that the building material stock in Lixia District in 2017was 142.31 Mt,compared with 84.46 Mt in 2003,an increase of 69%.Among all the functional types of buildings,housing is always the most important type in the district.From 2003 to 2017,the material stock of reinforced concrete buildings increased rapidly.In 2017,the stock of reinforced concrete structures became the most important structure type,surpassing that of brick-concrete structures.Behind the growth of building material stock is the huge demand for building materials,with the demand for steel,cement,lime and glass skyrocketing over the past 15 years,increasing by more than 150%.From the point of view of spatial distribution,the growth of building materials in Lixia District show a trend of expansion from the Midwest to the east and south.The building material stock of new and old urban areas presents different evolution paths.The old urban areas tend to be saturated with building material stock,while the new urban areas have experienced amazing expansion.There is a big difference between the inflow and outflow of building materials in the distinct,the amount of inflow into the building system is about four times the mass of outflow.From 2003 to 2017,the cumulative contribution rates of population effect,economic effect,urbanization effect and technology effect to the growth of building material stock were 22.92%,427.59%,115.24%and-15.24%,respectively.For Lixia District,the carbon emission per unit building area varies greatly in different building functions and building types.In addition,the environmental impact of the whole building system can be significantly reduced by effectively recycling the building solid waste in the demolition stage and choosing green building structure types.Taking 2017 as an example,recycling treatment and selection of low-carbon structure types can reduce emissions of 8.09 t CO₂ eq and 8.25 CO₂ eq,respectively.Based on the research on the stock,flow and carbon emission of urban building materials,the following suggestions are proposed to solve the problems in the sustainable development of the current building system:The sustainable development of urban building system involves multiple stakeholders such as government,enterprises,organizations and the public.Therefore,it is necessary to consider the sustainable development of urban building system from the perspective of each stakeholder.That is,by innovating the cooperation of multiple stakeholders,a benign interactive sustainable development mode of urban building system is formed,which is dominated by the government,led by the construction industry,actively participated by social organizations,and strongly supported by the public.At the macro policy level,the government promotes the sustainable development of the urban building system by strengthening building material management and rationally formulating spatial planning.At the micro application level,enterprises use green building materials and innovate construction methods to promote the sustainable development of urban building system At the organizational level,the sustainable development of urban building system can be accelerated by giving full play to the role of universities and cultivating innovative talents.Finally,at the personal level,the public can advocate green consumption and establish low-carbon concept to support the sustainable development of urban building system.