基于两步移动搜索法的昆明市五华区义务教育资源可达性评价

义务教育资源空间可达性直接关系到学生上学的方便程度,是反映地区教育发展水平和教育资源均衡性的重要指标。本文选择昆明市五华区为研究区,通过综合利用GIS空间分析和两步移动搜索法来分析该地区的义务教育资源可达性。首先,根据居民点的位置生成泰森多边形,并以泰森多边形为基本分配单元;然后,分别采用两步移动搜索法和引力法对研究区的中小学教育资源进行可达性评价;最后,将评价结果进行对比进而评估不同方法的优劣。结果表明:1)研究区义务教育资源的整体可达性不高;2)研究区义务教育资源可达性存在明显的空间异质性,且主要表现为显著的城乡差异性;3)两步移动搜索法在评价教育资源空间可达性时优于其他方法的评价结果。研究结果可为五华区义务教育资源的空间优化配置提供决策支持。     

天津市市内六区基础教育资源空间可达性评价

教育资源空间可达性评价与研究可客观反映地区教育教学资源的空间分布状况,为教育资源空间布局的合理配置和优化提供科学依据。选择天津市市内六区为研究区,以街道为统计单元,利用两步移动搜索法对研究区内各街道的入学(小学和中学)可达性进行测算,分析了天津市市内六区基础教育资源空间分布特点。结果表明,天津市市内六区入学可达性在空间上存在显著差异,呈现以中心向四周逐渐降低的趋势;高可达性主要集中在中心地区街道,基础教育资源过剩地区和稀缺地区呈两极分化的格局;且与街道人口的空间分布不匹配。     

基于GIS的两步移动搜寻法在北京市就医空间可达性评价中的应用

传统上用行政区内每千人病床数等指标来评价就医的空间可达性,并未考虑医院(供给)与人口(需求)的空间分布差异性及两者可跨越行政区界的潜在相互作用。基于GIS的移动搜寻法使用较小普查单元的人口数据,解决了内在的人口空间分布问题;移动搜寻域可以跨越行政区界,更合理地考虑病人与医院潜在的相互作用。本文通过北京市就医空间可达性的实证研究,展现了基于GIS的两步移动搜寻法在公共服务空间可达性评价方面的重要作用。     

北京城区就医可达性评价及空间特征分析

以GIS网络和空间分析技术为基础,运用两步移动搜寻法对北京市城六区医疗服务的可达性进行了研究;综合比较了地面交通和轨道交通两种出行方式下的就医可达性结果,并对空间分布特征进行了分析,为相关部门设施规划和资源分配提供了重要依据。分析结果表明,北京城区就医可达性分布不均衡,呈从中心向外降低的圈层结构。     

基于GIS医疗设施空间可达性的研究——以大连市为例

基于可达性相关理论,以GIS网络和空间分析技术为基础,运用改进的潜能模型和两步移动搜寻法,对大连市各社区人口和医院进行叠加分析,将标准化的可达性数值进行插值处理,使之空间可视化,探究了大连市中山区、西岗区、沙河口区人口和二级以上医院空间分布现状,并对大连市医疗可达性进行了评价。结果显示:大连市医疗设施北部集中,总体分布不均。西岗区医疗可达性总体状况良好;中山区人口分布密集区,医疗可达性较好;沙河口区可达性较差,亟待提高。两步移动搜索法能更有效反应区域医疗可达性的空间分异。     

一种北京城区避难场所可达性评价方法

针对传统两步移动搜寻法应用于避难场所可达性研究中存在的中心供给、统一阈值及无距离衰减的问题,提出了"入口供给、分段阈值、高斯距离衰减"的优化方案。入口供给更符合人类的认知规律,分段阈值则充分考虑了避难场所的面积因素,高斯距离衰减符合可达性随距离递减的规律。改良两步移动搜寻法能够较好地揭示城市应急避难场所与人口相互作用的规律。基于ArcGIS平台,将改良两步移动搜寻法应用于北京城区应急避难场所的可达性研究,获得更加真实、可靠的评价结果,展现了改良两步移动搜寻法在公共服务空间可达性评价方面的重要作用。     

基于GIS的公共图书馆空间可达性分析

图书馆是公共文化服务的重要资源,其空间分布对城市科技文化服务能力具有重要影响。对公共图书馆的资源配置、空间分布现状进行研究,以期能为相关部门提供决策支持。以北京市主城区为例,采用高斯两步移动搜寻法,从供需角度定量分析了研究区内基于自驾和公共交通出行方式下的公共图书馆空间可达性。出行时间通过调用准确度更高的百度地图API得到。结果表明,北京市主城区公共图书馆的空间可达性整体较好,但资源布局不均衡,自驾出行方式可达性整体上优于公共交通出行方式,后期需增加移动图书馆并改善公共交通,以期提高整体服务能力。     

六盘山地区中学教育资源空间可达性分析

针对当前大范围集中特困地区的中学教育资源空间可达性研究较为欠缺的问题,该文以六盘山地区为研究对象,通过网络爬虫获得1 415所中学和1 157个居民点位置及相关属性,辅以道路和人口等数据,运用改进的潜能模型,测算分析中学教育资源的空间可达性。结果表明:六盘山地区中学空间可达性整体有待提高;城乡差异显著,多民族聚居区、部分县区交界地带存在大范围中学空间可达性偏低现象;交通发达、路网密集区域的中学空间可达性较高。本研究为贫困山区的教育资源空间优化方案的制订及教育扶贫提供一定的借鉴。     

改进两步移动搜索法的焦作公共交通可达性

针对大部分城市公交发展滞后、公交站点和公交线路供需不平衡等问题,该文采用统计数据与实调数据相结合的方式,利用两步移动搜索法,从供需的角度研究分析城区公交站点服务的空间可达性。以河南省焦作市为例,以城区街道办为基本研究单元,分别采用固定阈值的简单两步移动搜索法和基于实测数据拟合的增强两步移动搜索法,对焦作市公交设施可达性的空间布局和差异性进行研究。实验结果表明:焦作市城区公交站点服务可达性整体上比较差;城区公共交通资源发展不平衡,空间差异比较明显,公交站点供需相对平衡区域主要集中在城区中心城区,低值区主要集中在城区边缘;增强两步移动搜索法考虑了距离衰减对人们公交出行的影响,更能反映焦作市真实的公交状况。     

GIS下的北京城区应急避难场所空间布局与可达性研究

均衡布局是城市应急避难场所规划建设的重要原则,可达性能够有效评价应急避难场所布局的均衡性与合理性。以场所入口为供给点应用两步移动搜寻法进行应急避难场所可达性研究,通过对比不同服务半径的可达性值的分布,确定3000 m为北京已建成避难场所的适宜服务距离。分析3000 m应急避难场所可达性图,可得结论,北京城区应急避难场所还不能满足城区居民避难需求,避难人数缺口大,且布局不够均衡、合理,首都功能核心区及其周边可达性好,而边远区域则完全享受不到避难服务,避难场所空间分布公平性较差。     

基于可达性测度的公园绿地服务公平性时空分析

由于城区土地资源的稀缺性,公园绿地的供给与人口对绿地的需求往往难以匹配,出现了公园绿地空间分布不均衡和服务不公平性的现象。本文以两步移动搜索法的可达性测度为基础,开展武汉市主城区公园绿地社会公平性的时空分析研究。研究表明:新一轮规划实施后,从服务的整体效益来看,武汉市主城区公园绿地资源分配向着更趋于公平的方向发展;从公园绿地服务的空间格局来看,绿地可达性提高较为显著,可达性极低区域面积减少。     

Spatial and temporal variations of spatial population accessibility to public hospitals: a case study of rural–urban comparison

Quantification and assessment of nationwide population access to health-care services is a critical undertaking for improving population health and optimizing the performance of national health systems. Rural–urban unbalance of population access to health-care services is widely involved in most of the nations. This unbalance is also potentially affected by varied weather and road conditions. This study investigates the rural and urban performances of public health system by quantifying the spatiotemporal variations of accessibility and assessing the impacts of potential factors. Australian health-care system is used as a case study for the rural–urban comparison of population accessibility. A nationwide travel time-based modified kernel density two-step floating catchment area (MKD2SFCA) model is utilized to compute accessibility of travel time within 30, 60, 120, and 240 min to all public hospitals, hospitals that provide emergency care, and hospitals that provide surgery service, respectively. Results show that accessibility is varied both temporally and spatially, and the rural–urban unbalance is distinct for different types of hospitals. In Australia, from the perspective of spatial distributions of health-care resources, spatial accessibility to all public hospitals in remote and very remote areas is not lower (and may even higher) than that in major cities, but the accessibility to hospitals that provide emergency and surgery services is much higher in major cities than other areas. From the angle of temporal variation of accessibility to public hospitals, reduction of traffic speed is 1.00–3.57% due to precipitation and heavy rain, but it leads to 18–23% and 31–50% of reduction of accessibility in hot-spot and cold-spot regions, respectively, and the impact is severe in New South Wales, Queensland, and Northern Territory during wet seasons. Spatiotemporal analysis for the variations of accessibility can provide quantitative and accurate evidence for geographically local and dynamic strategies of allocation decision-making of medical resources and optimizing health-care systems both locally and nationally.     

基于海量 POI 数据的城市小学教育资源信息的提取与分析

通过网络爬虫获取海量POI数据具有巨大的应用前景。文中利用改进后的两步移动搜索法,计算居民区的教育资源可达性,评价以市为单位的小学教育资源的状况,将各市的GDP与教育资源可达性进行相关性分析,评价各省经济发展与城市教育发展的相关程度,为政府部门提供决策依据。同时,研究POI数据的预处理方法和分类方法。     

改进G2SFCA的深圳市室内应急避难场所空间可达性研究

以深圳市为研究区，在考虑距离衰减效应的重力型两步移动搜索法（gravity two-step floating catchment area method，G2SFCA）基础上，引入Huff模型，并考虑需求点位置要素及地形要素，分别从供给点竞争、需求点定位、路网距离优化三方面对G2SFCA进行改进，并采用改进的G2SFCA对深圳市室内应急避难场所空间可达性进行研究。实验结果表明，改进的G2SFCA不仅能很好地揭示深圳市各社区室内应急避难场所的空间可达性，而且也能有效反映避难场所可达性与人口密度分布的空间匹配规律，较其他模型更符合现实情况；已建成室内应急避难场所数量、容纳人口及空间可达性的统计与分析结果真实、可靠，相关结论可为深圳市未来的防灾工作以及室内应急避难场所的空间规划与建设提供参考。     

The accessibility analysis of multiple public facilities in the central urban areas based on multi-transportation modes: A study in Chengdu

With the rapid development of social economy in Chengdu, it is of great significance to analyze the accessibility of a public facilities resources, and services in respective regions for the spatial planning of public facilities and the optimization of urban construction in Chengdu. Most existing studies only consider the accessibility of a single public facility under a single transportation mode studying facilities at the same level. In this research, with the consideration of all these factors mentioned above, an improved 3-step floating catchment area (3SFCA) model of multi-transportation modes is introduced to analyze the accessibility and spatial distribution of multiple types of public facilities under multiple traffic modes. The new model classifies the grade of public facilities and calculates the service accessibility of public facilities under the driving, public transport, cycling, and walking modes in the five dimensions of education, medical care, commerce, transportation, and leisure in the central urban areas of Chengdu. Through the comparative analysis of multiple models, we found that the improved 3SFCA can more accurately evaluate the accessibility of all dimensions of public facilities in central urban areas of Chengdu. The accessibility of compound public facilities in the central city is excellent. With the gradual expansion to the outward areas, the diversity and accessibility of compound public facilities gradually decreases. Furthermore, the accessibility distribution of public facilities in the study area is not balanced. The accessibility between the central urban areas and the marginal areas differs greatly and the spatial differentiation is substantial.     

莱西市医疗设施空间可达性研究

针对当前医疗资源分布不均的问题,本文以莱西市为例,以行政村为最小研究单元,借助GIS空间分析技术,采用改进的两步移动搜索和潜能模型法,对莱西市医疗设施空间可达性进行研究.结果表明:莱西市整体的医疗资源分配不均,具有明显的空间集聚特征,高值区域主要集中在中部地区,包括水集街道、沽河街道、望城街道和莱西经济开发区;低值区域...     

A spatiotemporal analysis of metro-stop based accessibility to bus services in Shanghai,China

Ground-level bus offers flexible services with relatively inexpensive fares and high-level accessibility, thus is the dominant feeder mode for metro in the majority of metropolitan areas in China. Intermodal transfer between the metro and bus networks is therefore a crucial element in the successful operation of an integrated transit system. In this circumstance, a key challenge is lack of appropriate methodologies to evaluate the spatial–temporal disparities of intermodal transfers between metro and bus. To address this issue, this research aims to promote an existing two-step floating catchment area (2SFCA) model by incorporating the temporal variability of service supply, demand, and travel time to provide a more realistic estimation of accessibility using smart card data and automatic vehicle location data. The proposed methodology was applied in a case study of the metropolitan area of Shanghai in the specific context of metro-stop based accessibility to bus services. The results of the case study show that the daily fluctuations in output metro-to-bus transfer accessibility values are highly sensitive to temporal dynamics of transfer time, service supply, and demand. It is hoped the results output here could give planners and policymakers greater insight into spatiotemporal dynamics on transfer accessibility, and help to establish an effective and efficient integrated transit system.     

地图水系综合中等高线簇与河网协同的汇水区域提取方法

在地图水系自动综合中河流选取需要建立对不同河流重要性程度的有效判别。由于河流汇水区域直接反映河流的作用空间,因而其面积大小成为关键性的量化指标。目前基于河流的汇水区域自动提取方法主要从河流单一要素出发,按“空间均衡竞争”思想平分河流之间的区域,由于未考虑地形因素使得提取的汇水区域往往存在偏差,而传统基于DEM的汇水区域提取虽然考虑了地形,但没有与河流目标建立显性的对应关系。河流是一种天然的沟谷地性线,与山脊线具有对生互补的空间耦合关系,本文提出了一种等高线簇与河网双要素协同的河流汇水区域提取方法,该方法对河流与等高线的目标集合构建约束Delaunay三角网(CD-TIN)并将三角形分类,对不同类型的三角形分别采用骨架线提取规则与梯度向量引导的分水线搜索规则提取分水线段,连接形成网络结构并依此计算各河段的汇水区域。实验结果表明,本算法能更准确地提取河流汇水区域,从而为河流综合选取提供有效支持。