空间数据分析与空间模型

虽然GIS已在各个领域得到广泛应用,但它相对较弱的空间分析功能正在限制其应用的广度和深度。文中系统论述了空间数据的基本特征,GIS中空间数据分析的基本需求,空间统计分析,空间数据探索分析以及空间模型,探讨了GIS与空间模型结合的必要性,结合途径以及结合中的问题与对策。     

Spatial structure analysis of a reptile community with airborne LiDAR data

The analysis of the spatial structure of animal communities requires spatial data to determine the distribution of individuals and their limiting factors. New technologies like very precise GPS as well as satellite imagery and aerial photographs of very high spatial resolution are now available. Data from airborne LiDAR (Light Detection and Ranging) sensors can provide digital models of ground and vegetation surfaces with pixel sizes of less than 1 m. We present the first study in terrestrial herpetology using LiDAR data. We aim to identify the spatial patterns of a community of four species of lizards (Lacerta schreiberi, Timon lepidus, Podarcis bocagei, and P. hispanica), and to determine how the habitat is influencing the distribution of the species spatially. The study area is located in Northern Portugal. The position of each lizard was recorded during 16 surveys of 1 h with a very precise GPS (error < 1 m). LiDAR data provided digital models of surface, terrain, and normalised height. From these data, we derived slope, ruggedness, orientation, and hill-shading variables. We applied spatial statistics to determine the spatial structure of the community. We computed Maxent ecological niche models to determine the importance of environmental variables. The community and its species presented a clustered distribution. We identified 14 clusters, composed of 1–3 species. Species records showed two distribution patterns, with clusters associated with steep and flat areas. Cluster outliers had the same patterns. Juveniles and subadults were associated with areas of low quality, while sexes used space in similar ways. Maxent models identified suitable habitats across the study area for two species and in the flat areas for the other two species. LiDAR allowed us to understand the local distributions of a lizard community. Remotely sensed data and LiDAR are giving new insights into the study of species ecology. Images of higher spatial resolutions are necessary to map important factors such as refuges.     

Spatial video and GIS

GIS elemental unit representations of spatial data are often defined in terms of points, lines and areas. However, another type of spatial data that is becoming frequently captured, but as yet is largely ignored in GIS, is that of video. While digital video recording is a commonly encountered medium in modern society and encompasses many forms, from simple personal camcorders through to sophisticated survey and surveillance systems, its geographical representation in a GIS has not been fully examined or realised. In the majority of cases the video footage is usually captured while the device and/or the objects being viewed are in motion. What is of particular interest is when video streams can be, or have been, associated with spatial data such as location and orientation to create geographically referenced videographic data, which, for simplicity, will be defined as spatial video. Fundamentally, the nature of video is to record space, so when spatial properties can be accurately acquired and associated with this footage, an important geographical element can be considered for integration and analysis within a GIS.

Existing spatial video systems, both commercial and research, are predominantly used in survey or LBS roles and are usually bespoke and application specific. These systems do not model spatial video to any recognised standards that is generalised to be both data and platform independent. They do not support GIS integration and/or analysis from a purely spatial content perspective. A video-image/remote-sensing centric approach prevails where usage options range from simple visualisation interfaces to interactive computer vision systems. What has been largely overlooked is a spatial approach where the inherent geographical extent recorded in each video frame can be modelled and used in a geo-spatial analysis context. While this modelling approach has not been fully realised, it does exist in a GIS form based on Open Geospatial Consortium standards, where the spatial context of video is defined in a structure called a ViewCone. However, a ViewCone only defines a 2D model of the geographical extent of each frame and is restricted to a three-or-five sided polygon representation.

Thus, this article examines the potential of modelling spatial video through the use of elemental data types within GIS; gives some examples of using this approach; describes some problems in using spatial video within GIS; and then demonstrates how these problems are being solved. This is done in three stages: Firstly, a detailed overview of spatial video in its current GIS role is provided – this is achieved through a complete introduction to the distinct elements of spatial video followed by a review of its use in both commercial and academic application areas. Secondly, a brief theoretical overview of an alternative GIS-constrained ViewCone data structure is given that defines a more flexible spatial video model for both 2D and 3D GIS analysis and visualisation. Thirdly, a selective sample of results is presented based on an implementation of this approach being applied to a constrained spatial video data source in a specific study area.     

Integrating GIS and spatial data analysis: problems and possibilities

Abstract

This article is an agreed summary of a workshop held in Sheffield between 18-20 March 1991. The focus here is on three of the themes of the workshop: the mutual benefits of closer links between geographical information systems (GIS) and the methods of spatial data analysis (SDA); the specific areas of SDA that should be linked with GIS; how the linkage should be made in practice. Directions for future research are also reviewed. The emphasis throughout is on statistical SDA and principally from the perspective of human rather than physical geography.     

GIS中的空间基准问题

GIS建设中空间基准的统一是GIS数据质量、数据共享、数据使用的基础。在我国GIS建设中普遍存在着空间基准不一致的问题。该文分析了我国GIS建设中空间基准存在的主要问题 ,并在此基础上给出了GIS建设中统一空间基准的方案、方法和步骤     

GIS空间索引方法述评

地理信息系统的主要任务之一是有效地检索空间数据及快速响应不同用户的在线查询。传统的索引方法只能解决一维查询问题,无法满足地理信息系统的要求。该文介绍了GIS中具有代表性的三类空间索引方法,即基于点区域划分的索引方法、基于面区域划分的索引方法和空间实体的地址编码索引方法,并且进行了分析对比。     

Split-Match-Aggregate (SMA) algorithm: integrating sidewalk data with transportation network data in GIS

Sidewalk geodata are essential to understand walking behavior. However, such geodata are scarce, only available at the local jurisdiction and not at the regional level. If they exist, the data are stored in geometric representational formats without network characteristics such as sidewalk connectivity and completeness. This article presents the Split-Match-Aggregate (SMA) algorithm, which automatically conflates sidewalk information from secondary geometric sidewalk data to existing street network data. The algorithm uses three parameters to determine geometric relationships between sidewalk and street segments: the distance between streets and sidewalk segments; the angle between sidewalk and street segments; and the difference between the lengths of matched sidewalk and street segments. The SMA algorithm was applied in urban King County, WA, to 13 jurisdictions’ secondary sidewalk geodata. Parameter values were determined based on agreement rates between results obtained from 72 pre-specified parameter combinations and those of a trained geographic information systems (GIS) analyst using a randomly selected 5% of the 79,928 street segments as a parameter-development sample. The algorithm performed best when the distances between sidewalk and street segments were 12 m or less, their angles were 25° or less, and the tolerance was set to 18 m, showing an excellent agreement rate of 96.5%. The SMA algorithm was applied to classify sidewalks in the entire study area and it successfully updated sidewalk coverage information on the existing regional-level street network data. The algorithm can be applied for conflating attributes between associated, but geometrically misaligned line data sets in GIS.     

基于GIS的北京市商业空间活动分析

地理信息系统发展至今已有40余年,技术的进步、用户的需求以及理论与方法的成熟,促使地理信息技术应用不断向深度和广度发展,但其应用领域还主要局限于城市规划、土地利用、设施管理等与空间信息直接相关的领域,而作为国民经济最活跃部门的商业流通领域GIS应用所见不多。文章以北京市作为实证分析对象,基于地理信息系统方法建立了矢量格网矩阵模型,并在此基础上构建了商业网点密度分析、商圈影响范围分析、商业空间查询分析等空间分析方法,并以北京市商业空间数据为基础进行了实际验证。     

遗传算法和GIS结合进行空间优化决策

资源的有效利用和管理往往涉及到空间的优化配置问题。例如需要在空间上确定n个设施的最佳位置。当选址问题涉及多个目标和不同的约束性条件时,就会变得十分复杂。利用一般的brute-force搜索方法无法对涉及高维数据的问题进行求解。利用遗传算法和GIS结合来解决复杂的空间优化配置问题,具有智能的搜索方法可以大大提高空间的搜索能力。在基于进化的优化过程中,根据GIS的空间数据来计算不同解决方案 (染色体) 的适应度。针对不同的应用目的,GIS可以给出不同的适应度函数。实验表明,所提出的方法比简单的搜索方法和退火算法有更大的优越性。该方法在处理复杂的空间优化问题有更好的表现。     

Providing spatial statistical data analysis functionality for the GIS user: the SAGE project

Geographic representation has become more complex through time as researchers have added new concepts, leading to apparently endless proliferation and creating a need for simplification. We show that many of these concepts can be derived from a single foundation that we term the atomic form of geographic information. The familiar concepts of continuous fields and discrete objects can be derived under suitable rules applied to the properties and values of the atomic form. Fields and objects are further integrated through the concept of phase space, and in the form of field objects. A second atomic concept is introduced, termed the geo‐dipole, and shown to provide a foundation for object fields, metamaps, and the association classes of object‐oriented data modelling. Geographic dynamics are synthesized in a three‐dimensional space defined by static or dynamic object shape, the possibility of movement, and the possibility of dynamic internal structure. The atomic form also provides a tentative argument that discrete objects and continuous fields are the only possible bases for geographic representation.     

GIS支持下的澜沧江流域云南段土壤侵蚀空间分析

利用ArcView3.2和ARC/INF08.1软件,通过图层叠加、统计分析和缓冲区分析等,提取西南纵向岭谷区澜沧江流域云南段的不同类型和强度的土壤侵蚀与地形坡度、土地利用/土地覆盖现状、土壤类型和分布、大雨日数以及河流、道路两侧的缓冲区等的相应数据,计算出土壤侵蚀综合度。结果表明,研究区不同坡度等级中,15°²5°坡度上的土壤侵蚀最强,其次为8°¹5°坡地和4°⁸°坡地;>25°坡地上则较小;不同用地类型的土壤侵蚀程度不同,总体上,旱耕坡地的土壤侵蚀较草地严重,而草地又较林地严重;在各种土壤类型中,黄壤和石灰土的土壤侵蚀最为突出,其次为红壤、黄棕壤和南方水稻土等;河流两侧和道路两侧的土壤侵蚀都较整个流域要严重,而河流两侧又略重于道路两侧;当多年平均大雨日数小于20日时,土壤侵蚀程度基本上随大雨日数的增加而增加;当大雨日数大于20日时,土壤侵蚀程度反而较小,原因在于前期大雨冲刷侵蚀,带走了地表的疏松物质。研究结果可为有针对性地防治水土流失、减少河流泥沙和水库淤积提供依据。     

探索性空间分析及其与GIS集成模式探讨

探索性空间分析基于让数据说话的理念,可以避免野值或非典型观测值的误导。在对探索性空间分析的基本原理和概念界定的基础上,探讨交互式和动态空间数据分析、地学可视化及可视化空间分布、确认性空间分析、空间数据挖掘等探索性空间分析的主要技术。由于统计分析软件和GIS的数据格式差异很大,直接将二者简单集成存在一定困难,因此切实可行的集成方式是采用对象连接和嵌入(OLE)技术,分别调用统计分析软件的探索性分析功能(或者函数)以及GIS的地图显示和空间分析功能,并进行必要开发,实现二者的集成。最后对探索性空间分析的发展方向进行展望。     

Municipal GIS and the enterprise data model

Abstract

The City of Scarborough, like many corporations, recently re-evaluated its information technology requirements. The decision was made to model the City's needs in terms of activities and data requirements, concentrating on the Municipal Data Model. First, a two year study was undertaken to understand the business activities of all the disparate components that make up the corporation. This study resulted in individual Information Resource Plans (IRP) for each department. A third year was spent in reconciling the many separate documents and creating a high-level Conceptual Data Model for a Corporate Information System. Of the thirteen broad data groupings, four were assigned to the GIS Group for the design of Detailed Data Models and to populate the resultant databases. The GIS Group, in fact, were to initiate the new Information System for the entire City. The modelling sessions involved hundreds of users from the entire user community in small and large groups, in intensive entity-definition activities, in technical review sessions and in the general examination of context. The detailed models were validated by involving still more users and by testing the model in prototypes, special projects and joint ventures. The GIS Project has demonstrated that data modelling is an effective and realistic method of reflecting the municipality as an enterprise.     

Many sorted algebraic data models for GIS

Although many GIS data models are available, a declarative, operational, well-defined, implementation-independent, and object-oriented language is lacking. Based on the theory of many sorted algebra, this work presents a family of geometric data models. Some geographical data models of urban information systems are illustrated using homomorphism. According to the results, the preferred characteristics of mixing declarative and operational statements, multiple representations, tight interdependency among objects, and integration of vector and raster based systems can be achieved through this mechanism.     

Geographical data handling and GIS in China

Abstract

Abstract Chinese governments have long paid a great deal of attention to the collection of geodata, and existing sources have been further enhanced by technological advances, notably in remote sensing. Progress has also been made with automated cartography. An expert working group has been examining GIS and it is recognized that a system combining both national and regional components is most appropriate for China. Three basic functions are envisaged for such GIS: comprehensive regional analysis, prediction of change and the sharing of data. Such systems must serve the needs of users and, in order to demonstrate potential applications, regional experiments are being undertaken, including examples of urban information systems, river basin information systems and specialized systems (e.g. for tourist and forest resources). In the next few years, the emphasis will be on research and on technological preparation for the adoption of GIS, including the use of an experimental set of geographical grid cells. Chinese scholars are also involved in international collaboration in the study of global problems and propose a cooperative programme for a global geographical information system.     

基于POI数据的郑东新区服务业空间聚类研究

探讨城市新区的服务业空间格局,对城市新区规划和服务业空间布局的优化具有重要指导意义。采用POI数据对郑东新区服务业的总体、分行业空间布局进行聚类,结果显示：① 在总体上,聚类呈现“414”的空间体系,各聚类所在区域的通达性较好;服务业在功能区内部聚集和跨越功能区聚集并存;噪声点分布零散,局部出现了服务业聚集的潜力区域;空间临近效应、行政力量带动和市场导向作用导致服务业空间极化特征明显。② 从分行业来看,部分行业的重要空间节点分布存在一定差异,CBD核心区和商住物流区成为各行业空间节点的分布区域;部分行业的空间节点与功能区的产业定位存在吻合与错位特征。最后,从规划视角提出了郑东新区不同功能区产业结构优化的方向。     

改革开放以来延吉市城市空间扩展过程与演变趋势研究

基于1976、1992、2001、2008年的遥感影像,利用“等扇分析法”和基于不等时距的灰色系统方法,分析了延吉市近32年的城市空间扩展过程。在自然、经济、政治、交通等四个主要因素作用下,延吉市城市形态已由团块状转变为星状,城市空间扩展主要沿“布尔哈通河”东西两向、“烟集河”向北三个条带扩展,且这三个条带扩展强度较高;2001~2008年间,城市空间在各方向的扩展差异减小,改变了以往过分集中于少数几个方向的状况。从不等时距的灰色预测结果看,2015、2020年延吉市城市建成区的面积将分别达到106.621和149.516km²,仍将保持快速扩展趋势,且扩展数量较大,而目前延吉市除农业、生态保护用地外,周围可供城市化的土地资源较少,因此建议积极进行规划管理,集约利用土地,实现科学发展,避免城市过分膨胀。