低碳视角下城市空间形态紧凑度研究

全球气候变化背景下,构建功能紧凑的低碳城市空间形态已成为世界各地城市实现低碳化可持续发展的主要途径之一。但目前的城市形态研究主要集中在城市外部空间,缺乏对城市内部功能空间紧凑度的量化。从实现低碳城市的视角,提出了城市内部功能空间形态紧凑度的量化指标,用以探讨实现低碳城市的城市空间形态特征;以商业、医疗、教育和文化娱乐等4种重要服务设施布局为基础,构建了城市功能空间紧凑度指数,对不同规模、不同地理条件类型的8个案例城市进行定量研究,实证了城市内部“功能空间紧凑度”指标较城市外部“形态紧凑度”指标能够更好的反映城市形态的紧凑性内涵,适用于评价各类城市空间形态的低碳发展模式。

Study on spatial form compactness from low-carbon perspective

It has been a great threat that CO₂ emissions is growing continuingly.Thus,the low-carbon urban form is focused by studies and has become a common pursuit because the city affects the global climate in the most intense ways.Scholars''study shows that compact urban form can reduce the unnecessary urban travel,and achieve low-carbon city,or in other words,low-carbon urban form refers to "compact city" which resists the high-carbon urban sprawl. This research compared all the indexes used in measuring the compactness of urban form, and advanced the "function space compact index" to evaluate the compactness in perspective of a city function.Based on the quantitative classification of urban form,this paper,by using quantitative index system,employed service radius of four major service facilities, commercial,educational,medical,sports and cultural facilities,to calculate the "function space compact index" and evaluate the compactness.And due to the different intensities of service as the different levels of city service facilities,this paper classified commercial, medical,educational and other services when it talked about "function space compact index". "Function space compact index" is all the weighted averages of the respective class of service,as this research considered all the functional facilities''class. A city''s development is limited by the natural and geographical environment,the compactness of its external space form is generally difficult to change.So,the study focused on a city''s functional space compactness.In other words,whether a city can achieve compactness through the rational allocation of internal functions when a city cannot change its external morphology compactness depends on natural and geographical factors.As a result, the study chose eight cities which were divided into four categories based on natural and geographical factors,Plain City,Mountain City,Split City,and Coast City.Through analysis the eight cities in GIS data 2008,the research verified the more application of "function space compact index" than other external form indexes.The study shows that city functions spatial compactness could be effectively improved by optimizing the allocation of urban function services facilities,improving the mix-used development mode and operating reasonable urban land intensity.Then the compact urban form will improve the air environmental quality and achieve the low-carbon city goal.Especially in the development of new town,or new city centre,to give priority to guarantee the service facilities land supply is the important way to enhance the compactness of the urban form,and to expand the implementation of low-carbon city.