基于决策树的城市早期地下工程更新改造模式规划评价方法

Decision Tree-Based Planning Assessment Method for Renewal and Transformation Modes of Aged Urban Underground Space Projects

为更加合理高效地挖潜存量地下空间资源、助力“实施城市更新行动”,提出基于决策树的城市早期地下工程更新改造模式的规划评价方法。基于国内外代表性早期地下工程更新改造和相关地下工程开发利用案例分析,将城市早期地下工程更新改造模式分为地下动态交通、地下市政公用、地下仓储物流、地下商业、地下文娱、地下社区服务、地下静态交通7个大类和21个小类;建立城市早期地下工程更新改造模式的影响因素特征指标体系,包括用地类型、结构形态、面积、埋深和周边区位条件;构建决策树样本集,包括24个基本样本和1605个构造样本。针对城市早期地下工程更新改造的特点,在决策树方法中提出“大类-小类”强对应原则,以及适用于早期地下工程更新改造决策树的可靠性评价和二次决策方法。模型评估结果表明,该方法的预测准确度足以保证后续决策的可靠性。青岛市中山路片区实例研究表明,该理论方法具有较强的可行性。

To effectively utilize existing underground space resources and facilitate the implementation of urban renewal action,herein,a decision tree-based planning assessment method for the renewal and transformation modes of aged urban underground space projects is proposed.Furthermore,based on the case studies of exemplary aged underground space projects around the world,the renewal and transformation modes of such space projects are divided into seven principal categories(underground dynamic transportation,municipal utility,storage and logistics,commerce,entertainment,community service,and static transportation)and 21 subcategories.A characteristic index system for factors influencing the renewal and transformation modes is established,which includes land type,structure form,area,buried depth,and surrounding location conditions.Additionally,a sample set comprising 24 basic samples and 1605 constructed samples is built for the decision tree of aged underground space project renewal.According to the characteristics of aged urban underground space projects,a strong correspondence principle of"principal categories-subcategories"is proposed in the decision tree method along with a suitable reliability evaluation and quadratic decision method for the decision tree.Results of the model assessment indicate that the prediction accuracy of the proposed method can guarantee a reliable decision-making process.A case study of the Zhongshan road area,Qingdao,shows strong feasibility of the proposed theoretical method.