基于GIS热点技术的低碳出行街区建成环境特征探析

Characteristics of built environment in low-carbon travel block based on GIS hotspot technology

为解决街区规划中缺少通过量化街区环境特征引导居民低碳出行的问题,首先,建立一套识别低碳出行街区的方法,采用微信定位、规划部门资料及实地调研数据,构建了以交通调查四要素(出行方式、出行时间、出行目的、出行频率)为研究框架的指标评价体系;引入GIS热点技术,对表征碳排放的各指标进行热点分析,以陕西蒲城县老城区为例筛选出低碳出行街区。然后,构建表征建成环境的指标体系,从建成环境特征角度分析该街区内居民低碳出行的原因,得出有利于低碳出行且适用于蒲城县城及类似小城市的街区改造量化建议。研究结果表明:居住与其他类型建筑的面积比宜为4∶1~3∶1;重点发展自行车出行模式,自行车车道间隔宜为350~450m,可步行道路占道路总面积比宜为15%~20%,且限制道路宽度;以150 m为半径的公交站点覆盖率为40%~50%,以50m为半径的购物服务设施覆盖率为45%~60%,以100m为半径的娱乐服务设施覆盖率为50%~70%。该结果证实了前人提出的"功能混合"及"密路网"利于居民低碳出行,同时还发现并非容积率越高越利于低碳出行,小城市人口数有限,职业岗位分布分散,不适合提高容积率配合公交系统的传统模式;并非公交站点覆盖率越高,越利于居民低碳出行,小城市公交高度普及反而使居民出行碳排放升高。该研究为街区的出行碳排放评价问题提供了新思路,为以低碳理念的街区规划提供依据。

In order to solve the problem in the neighborhood planning research on built environment to lead people to travel in a low-carbon identify low-carbon travel block have been firstly established. By using planning department data and field research data, an index evaluation of lacking quantitative way, a set of ways to ＂WeChat＂ positioning, system based on four factors of transportation survey： travel mode, travel time, travel purpose and travel frequency was constructed. The old urban district of Pucheng as example. Secondly, the index system to characterize the built environment was constructed, reasons for low-carbon travel in the neighborhood were analyzed from the perspective of built environmental characteristics, and suggestions for improvement of low-carbon travel in the old urban district of Pucheng and other similar cities have been obtained. The results show that ratio of residential building area to other types should be set between 4 ： 1 and 3 ： 1. The pattern of bicycle travel is mainly developed, and interval of bicycle lanes should be set between 350 m and 450 m. The ratio of pedestrian street occupying land area should be set between 15% and 20% and the width of road should be limited. The coverage ratio of bus stations with 150 m as radius should be set between 40% and 50%, the coverage ratio of shopping service facility with 50 m as radius should be set between 45% and 60%, and the coverage ratio of entertainment service facility with 100 m as radius should be set between 50% to 70%. The conclusion of research confirms ＂mix function＂ and ＂dense network of road＂ are helpful for residents to travel in a low-carbon way. At the same time, it is also found that not the higher plot ratio is more conducive to low carbon travel. Population of small city is limited, and the distribution of professional jobs is scattered, which is not suitable for improving the traditional mode of the volume ratio with bus system. Not the higher coverage rate of bus station is more conducive to residents for low-carbon travel. The high popularization of buses in small city increases carbon emissions for residents＇ travel. The study provides a new way of thinking about evaluation of travel carbon emissions in the neighborhood and put forward a basis for the planning of block with low-carbon idea. 6 tabs, 11 figs, 22 refs.