热带海岛城市居民慢行出行对土地利用的响应及碳减排机理——以海口市为例

Travel carbon emissions reduction from urban residents has a significant impact on the construction of low-carbon city. However, the study on the response of non-motorized transportation to land use and the mechanism of carbon emission reduction for city residents in tropical island are weak. Based on the urban community of Haikou City in Hainan Province as the basic unit, first of all, according to remote sensing images of the third Resource Satellite, UAV aerial data, and community interviews, this study selects the typical communities according to the built environment assessment of residents' non-motorized transportation. Then, conduct a questionnaire survey of typical community residents, the effects of built environmental variables such as land use spatial structure and mixed land use, and their change, on non-motorized travel and carbon emission were analyzed by structural equation model (SEM) for communities that the built environment changes significantly or not obvious, respectively. After that, in view of the different types of communities under the locked urban form, using multinominal Logit model (MNL) to analyze the impact of public facilities and non-motorized travel facilities on residents' non-motorized transportation and carbon emissions. At last, using the scenario analysis to simulate the carbon emission reduction potential for residents' non-motorized transportation by the optimization of land use spatial structure, which is represented by public facilities optimization, and the optimization of non-motorized travel facilities, which is represented by bicycle parking lot and lease point optimization. This study can provide theoretical guidance and practical experience for humanistic low carbon city and transportation system construction.

城市居民交通出行的碳减排对低碳城市建设具有重要影响。针对热带海岛城市居民慢行出行对土地利用的响应及碳减排机理研究薄弱问题，本研究以海南省会海口市城市社区为基本单元，首先，结合资源三号卫星遥感影像、无人机航拍数据和社区访谈，以居民慢行出行的建成环境评估为依据选择典型社区；然后，进行典型社区居民的问卷调研，对建成环境变化明显和不明显的社区，分别应用结构方程模型（SEM）分析土地利用空间结构、土地混合利用等建成环境变量及其变化对居民慢行出行及碳排放的影响；进而，针对城市形态锁定下的不同类型社区，运用多项Logit模型（MNL）分析公共设施和慢行出行设施布局对居民慢行出行及碳排放的影响；最后，应用情景分析法模拟以公共设施优化为代表的土地利用空间布局优化，和以自行车停车场和租赁点优化为代表的慢行出行设施优化对居民慢行出行的碳减排潜力，从而为以人文本的低碳城市与交通系统建设提供理论指导与实践经验。

城市建成环境是影响居民交通需求的根源，对居民出行行为决策产生“锁定效应”。如何优化建成环境、推动居民出行低碳化成为低碳社会构建的关键科学问题之一。海口市居民以电动车和小汽车出行为主，导致严重的交通治理问题，研究居民出行模式及其优化策略具有重要实践价值。因此，本项目以海口市为典型案例，基于高分辨率遥感影像、百度地图API和GIS空间分析技术，首先进行城市建成环境评估，根据居民出行行为问卷调查，以500m×500m格网为基本研究单元，利用多项Logit模型分析建成环境对居民通勤和非通勤出行的影响。进而，以公园绿地和医疗设施为例，以可达性和空间公平性为抓手，以改进的三步移动搜索法（3SFCA）为核心，进行公园绿地服务效率评估和公共医疗服务均等化评估，探究公园绿地和公共医疗设施布局优化对居民出行的影响。最后，针对电动车出行乱象，分析了建成环境要素优化下居民电动车出行行为的变化。.研究发现，建成环境要素与居民个体属性共同影响着居民的出行选择，提高居住地人口密度、土地利用混合度和就业可达性，可以提高居民慢行出行和公共交通出行的概率。不同交通方式下，公园绿地服务效率的空间差异明显，慢行出行的可达性和公平性均较差，优化公园绿地空间布局、加强慢行系统建设能有效改善公园绿地服务供给不均衡状况。海口市公共医疗服务短缺区域分布广泛，人口密度大、有贫困人口、最短就医耗时长的区域公共医疗服务严重不均等，医疗设施布局优化后可以基本实现服务的均等化。居住地人口密度高、路网密度高、公共交通可达性差、女性、低收入和低学历居民更倾向于选择电动车通勤出行，建设公交导向城市、优化高人口密度区道路设计等组合策略可以有效缓解电动车通勤出行乱象。城市建成环境度量指标体系、改进的3SFCA算法、公共服务空间可达性与公平性评价模型等理论和方法创新可以为低碳城市设计、公共服务布局均等化提供理论依据与案例支撑，具有重要的应用价值。