Study On Life-cycle Environmental Impacts Of Urban Residential Buildings And Regionalization Of Cities In China

Sustainable urbanization is an important part of entering the well-off society in anall-round way by2020and accelerating the transformation of economic and socialdevelopment in China. Urban residential buildings have presented a significantexpansion recently in association with rapid urbanization and increasingly rigiddemand on residential buildings. On the other hand, the large scale of constructingcities stimulated more the development of urban residential buildings, which increasedthe pressure of land use, water use, energy consumption, and environmental pollutionemissions in urban areas. The sustainable development ability of cities weakenedthereupon as well. Therefore, Quantitative studies on the environmental impact of thedevelopment of urban residential buildings are of significance in implementingurbanization development strategy, optimizing the urbanization pattern of differentregions, regulating and controlling the development of urban residential buildings.Based on the life cycle assessment of a standard building, this study developed theresearch framework of the environmental impact assessment of urban residentialbuildings on national level in China. The urbanization ratio, Living standards of urbanresidents and the structure of residential buildings of all287cities were taken intoconsideration in this research. After that, the regionalization of287cities was studiedbased on the perspective of the environmental impacts of urban residential buildings.The results showed that the floor area of urban residential buildings in287citiesin China was19.98billion m2in2010. The consumption of cement, steel, glass,aluminum, ceramics, and bricks in newly built urban residential buildings were162.1million tons (mt),40.7mt,2.2mt,1.5mt,13.9mt,9.7mt, respectively. The steel wasaccounted for49.3%of the environmental impacts of all building materials. Theenergy consumption, water use, COD, NH3-N, SO2, and NOx emissions of urbanresidential buildings reached436.7million tce (tons of coal equivalent),40.7billionm3,7.4mt,0.8mt,3.1mt,4.1mt, respectively. Among them, the impacts in the operationphase shared about89.2%on average. The scenario analysis revealed that theenvironmental impacts of urban residential buildings in2020would increase by30.6%-41.7%compared with that in2010. The study on the regionalization of287 cities based on environmental impacts of urban residential buildings revealed that, allcities were classified from zone I to zone IV. Zone I was accounted for8.3%of totalenvironmental impact of urban residential buildings. The COD，SO2emissions percapita in zone I were larger than that in zone I, II, III, i.e.,12.2kg,5.4kg, but the wateruse per capita was32.9m3. Zone II and zone III generated about1/3of totalenvironmental impacts, respectively. The residential land per capita in zone II was35.0m2. The energy consumption in urban residential buildings in zone III was567.1kgce.Zone IV shared28.5%of the total environmental impact of urban residential buildings.The water use per capita in zone IV were66.9m3, but the residential land per capitawas just24.5m2, which was much smaller than that in zone I, II, III. The researchsuggested that the differentiated development of urbanization pattern, reasonablevelocity of the development of urban residential buildings, promoting green residentialbuildings contributed to the sustainable development of urbanization strategy.