城市住宅建筑系统流量-存量动态模拟——以北京市为例

Dynamic modeling of stock and flow in an urban residential building system: A case study of Beijing

地面建筑物的累积与更新是城市化过程的结果与显性特征之一。城市建筑系统在不同层面上与外部环境系统进行着物质能量交换,对这种交互产生的资源压力与环境胁迫的关注,使其成为城市代谢研究领域中的热点问题。系统分析与模拟城市建筑物流量-存量的动态变化过程及其资源环境响应,对于揭示城市建筑系统代谢机理,提高城市总体规划精准性、强化资源系统韧性管理、提升废弃物处置效率等宏观战略具有重要意义。以北京市为例,基于Stella建模平台,构建了城市居民住宅建筑系统流量-存量的动态模拟模型,定量模拟了不同管理情景下钢材需求量与建筑拆除垃圾产生量的变化区间。结果表明:(1)基准情景下,北京住宅建筑新建流量前期增速较快,2005年达到峰值3024.1万m^2,而拆除流量约于2057年达到峰值,拆除面积为2073.14万m^2;城市住宅建筑存量最高值出现在2075年左右,面积为7.51亿m^2;(2)与基准情景相比,如果人均住宅建筑面积提高到45 m^2,从现在到模拟期结束(2019—2100)将增加钢铁需求量3251.65万t;而如果延长住宅建筑寿命至设计值,同期可减少钢铁需求量3022.9万t;(3)基准情景、大面积情景以及长寿命情景下,北京市城镇住宅建筑拆除垃圾峰值产生量分别为0.29亿t、0.39亿t、0.20亿t,政府管理部门应采取有针对性的应对措施,提前做出综合利用和处理处置方案。

Accumulation and renovation of ground buildings are the typical characteristics and inevitable results of the urbanization process.The resources and environmental pressure associated with energy and material flows between the urban building system and hinterland environment make building system a hot issue in the field of urban metabolism research.Systematic modeling of urban building flow-stock dynamics and related resources and environmental response are of great significance for macro-management such as urban spatial planning,urban resource management,and waste disposal.Using Beijing as the case city,we established a dynamic model for stock and flow of the urban residential building system with the STELLA modeling platform.The dynamic interval between the demand for steel and amount of demolition waste generated under different management scenarios was quantitatively simulated.The simulation results are as follows:(1)In the baseline scenario,the construction flow of residential buildings in Beijing increased rapidly,reaching a peak of 30.24 million m^2 in 2005;the demolition flow will peak in around 2057,with a demolition floor area of 20.73 million m^2.The highest value of the urban residential building stock will appear around 2075,with an area of 751 million m^2.(2)If the per capita floor area reaches 45 m^2,the total steel demand will increase by 32.52 million tons in the next 81 years(2019-2100);if the lifespan of residential buildings is prolonged to the design lifetime,the total steel demand will decrease by 30.23 million tons in the same period.(3)In the baseline scenario,large-area scenario,and long lifespan scenario,the peak value of demolition waste is 0.029 billion tons,0.039 billion tons,and 0.020 billion tons,respectively.These results shed light for policy makers to take prompt action and improve reuse and treatment levels of building demolition waste in the future.