效率与公平协调的公共空间导控值域研究——以TOD地块公共空间供应指标为例

A Threshold Control of Modeling Balance between Efficiency and Equity:The Case of Indexing of TOD Public Space Supply at the Block Scale

文章提出了一种新的金字塔模型,可帮助验证城市设计中公共空间弹性导控的值域取值。没有效率无从谈公平,公平是更高阶的效率。"效率-公平"协调的重点在于以"效率底线""功能品质优化""社会可持续"为出发点的值域确定。以上海33个中心区TOD地块基面公共空间为样本,将其行为学数据降维得出可达性、功能可见性、连续性三维度的主成分得分,通过拟合三维度之间的高低阶曲线函数关系,实证了可达性、功能可见性、连续性作为三个公共空间活动指示剂,依次处于金字塔模型的效率发展、品质发展、可持续发展层级,由此可指导TOD地块不同开发阶段的指标弹性控制。最后,以地块面积、地块开敞公共空间面积、室内基面接驳公共空间面积为例,验证基于三维度曲线拟合有效的公共空间供应指标的应用方法。

This research proposes a new pyramid model to help the threshold control practice of public space in urban design.There exists no equity without efficiency,and equity is a higher order of efficiency.The key point of“efficiency-equity”coordination is to find the threshold from“minimum for efficiency”to“maximum optimization for function and quality”or“maximum optimization for social sustainability”.The model takes urban base public space of 33 TOD blocks in the central area to sample the behavioral data and gets the principal component scores of accessibility,affordance and continuity from the PCA analysis of behavioral data.Through the component quadrant of the three components of the accessibility,affordance and continuity can be empirically concluded as comprehensive indicators of efficiency and equity,and are respectively at the three levels of efficiency priority,quality development and sustainable development in the pyramid model.This provides guidance for the TOD urban design control of different development stage.Besides,the physically featured index including the block area,open public space area and indoor urban base public space area are proved effective with thresholds.