A Review of: “Accuracy of Spatial Databases”. Edited by M. Goodchild and S. Gopal. (London: Taylor & Francis, 1989.) [Pp. 290.] Price £35.00.

The integration of multisource heterogeneous spatial data is one of the major challenges for many spatial data users. To facilitate multisource spatial data integration, many initiatives including federated databases, feature manipulation engines (FMEs), ontology-driven data integration and spatial mediators have been proposed. The major aim of these initiatives is to harmonize data sets and establish interoperability between different data sources.

On the contrary, spatial data integration and interoperability is not a pure technical exercise, and there are other nontechnical issues including institutional, policy, legal and social issues involved. Spatial Data Infrastructure (SDI) framework aims to better address the technical and nontechnical issues and facilitate data integration. The SDIs aim to provide a holistic platform for users to interact with spatial data through technical and nontechnical tools.

This article aims to discuss the complexity of the challenges associated with data integration and propose a tool that facilitates data harmonization through the assessment of multisource spatial data sets against many measures. The measures represent harmonization criteria and are defined based on the requirement of the respective jurisdiction. Information on technical and nontechnical characteristics of spatial data sets is extracted to form metadata and actual data. Then the tool evaluates the characteristics against measures and identifies the items of inconsistency. The tool also proposes available manipulation tools or guidelines to overcome inconsistencies among data sets. The tool can assist practitioners and organizations to avoid the time-consuming and costly process of validating data sets for effective data integration.     

Tuning the second-generation SDI: theoretical aspects and real use cases

Spatial data infrastructure (SDI) actors have great expectations for the second-generation SDI currently under development. However, SDIs have many implementation problems at different levels that are delaying the development of the SDI framework. The aims of this article are to identify these difficulties, in the literature and based on our own experience, in order to determine how mature and useful the current SDI phenomena are. We can then determine whether a general reconceptualization is necessary or rather a set of technical improvements and good practices needs to be developed before the second-generation SDI is completed. This study is based on the following aspects: metadata about data and services, data models, data download, data and processing services, data portrayal and symbolization, and mass market aspects. This work aims to find an equilibrium between user-focused geoportals and web service interconnection (the user side vs. the server side). These deep reflections are motivated by a use case in the healthcare area in which we employed the Catalan regional SDI. The use case shows that even one of the best regional SDI implementations can fail to provide the required information and processes even when the required data exist. Several previous studies recognize the value of applying Web 2.0 and user participation approaches but few of these studies provide a real implementation. Another objective of this work is to show that it is easy to complement the classical, international standard-based SDI with a participative Web 2.0 approach. To do so, we present a mash-up portal built on top of the Catalan SDI catalogues.     

Interactive Visualization Software to Improve Relief Interpretation Skills: Spatial Data Infrastructure Geoportal versus Augmented Reality

The improvement of geospatial thinking is essential for success in science, technology, engineering, and mathematics disciplines. Training based on the geovisualization and interpretation of landforms can develop the relief interpretation skill. The research reported here focuses on the study of relief visualization and interpretation, using results from a workshop performed with forty-six university students using different displays of geovisualization in a Spatial Data Infrastructure (SDI) geoportal: LiDAR digital surface model, HillShade digital terrain model, digital elevation model, slope model, high-resolution orthophoto, and topographic map. The results are compared with those of another workshop on the same topic carried out with augmented reality (AR) technology. The relief interpretation skill improvement was measured before and after each of the workshops using the Topographic Map Assessment test. The results with the SDI geoportal showed a significant gain in relief interpretation skill between pretest and posttest scores but less than the gain obtained with AR. No differences were found due to the gender of the participants in either case. Key Words: augmented reality, geospatial thinking, landform interpretation, relief interpretation skill, Spatial Data Infrastructure.     

The role of sub‐national government and the private sector in future spatial data infrastructures

A Spatial Data Infrastructure (SDI) facilitates and coordinates the exchange and sharing of spatial data between stakeholders in the spatial data community. With this objective in mind, countries throughout the world are developing SDIs to manage and utilize their spatial data assets more effectively. These countries are developing SDIs to assist in various kinds of decision‐making at different levels of government jurisdictions that have an important impact within their national boundaries. However, current research shows that SDI is understood and described differently by stakeholders from different disciplines and different jurisdictional levels. Therefore, in many cases, SDI initiatives remain very much an innovation, even among practitioners. There are still uncertainties regarding the benefits and identities of SDIs, particularly in connection with how they evolve over time to meet user needs. This paper reviews and assesses the development of SDIs throughout the world over the past 15 years and the leadership role of national governments in SDI creation. This assessment is based on the SDI activities of various jurisdictions including Asia‐Pacific, Australia, North America, and Europe, and research into the worldwide effects of spatial information clearing houses. This assessment includes a discussion on emerging trends in SDI development, with particular reference to the increasingly important role played by sub‐national governments and the private sector within the framework of SDI development. The paper concludes with a discussion of the implications for future SDI development, including the delivery of a virtual world that has a particular focus on facilitating decision‐making at a community level within a national context.     

A modelling framework for the study of Spatial Data Infrastructures applied to coastal management and planning

The continuous development of Spatial Data Infrastructures (SDI) provides a favourable context for environmental management and planning. However, it appears that the actual contribution of SDIs should also depend on the correlation between users’ expectations and the services delivered to them. Several studies have addressed some organizational, methodological and technological aspects of the development of SDIs. However, only a few studies have, to the best of our knowledge, studied SDI use at large. This article introduces a methodological approach oriented towards the study of the relationship between SDIs and the users interacting with them as part of their professional practices. Our study is applied to coastal zone management and planning in France. This approach combines structural and data flow modelling. The former is based on Social Network Analysis (SNA) and the latter on Data Flow Diagrams (DFD). This modelling approach has been applied to an online questionnaire and semi-structured interviews. The results identify the SDIs, geographical data flows and institutional levels implied in French coastal zone management and planning.     

中国县域国土空间集约利用计量测度与影响机理

土地利用问题日益成为中国经济发展的重要约束力之一。快速城镇化背景下城镇和乡村的快速扩张吞噬了宝贵的土地资源,粗放非集约的利用方式更加剧了土地资源的浪费。从国土空间集约利用的影响机理出发分析中国县域国土空间集约的影响机理对指导集约利用实践以及宏观集约利用政策瞄准和政策矫正都具有特殊意义。综合运用OLS模型、空间面板滞后模型和空间面板自相关模型以GIS和Matlab为技术平台,构建中国县域发展基础数据库 (1992-2010年),定量刻画中国2286个县级单元的空间集约利用度时空变化格局,计量分析社会经济发展、自然环境本底、区位交通地理、宏观战略政策和历史基础5大类变量17项具体因素的影响机理。研究结果表明,空间面板数据模型的整体显著性和可信度检验略高于一般面板数据OLS模型;在固定相关效应后对各因素的影响机制进行了检验,表明工业化、城镇化、经济发展水平、区位、交通和宏观战略政策等因素对县域国土空间集约利用的影响较为明显。自然环境因素弱于社会经济因素。被忽略的历史因素对县域国土空间集约利用具有极显著的影响。未来县域国土空间集约利用应因势利导,强化有利因素,减小不利因素影响。提高工业化和城镇化发展水平和质量。发挥市场的主导作用,完善土地市场和运行机制。优化国土空间集约利用调控政策和管治手段,制定差别化的空间集约利用政策。以资源环境承载力为基础和约束最大限度地提高投入和产出水平。     

A fast candidate viewpoints filtering algorithm for multiple viewshed site planning

ABSTRACT

The aim of site planning based on multiple viewshed analysis is to select the minimum number of viewpoints that maximize visual coverage over a given terrain. However, increasingly high-resolution terrain data means that the number of terrain points will increase rapidly, which will lead to rapid increases in computational requirements for multiple viewshed site planning. In this article, we propose a fast Candidate Viewpoints Filtering (CVF) algorithm for multiple viewshed site planning to lay a foundation for viewpoint optimization selection. Firstly, terrain feature points are selected as candidate viewpoints. Then, these candidate viewpoints are clustered and those belonging to each cluster are sorted according to the index of viewshed contribution (IVC). Finally, the candidate viewpoints with relatively low viewshed contribution rate are removed gradually using the CVF algorithm, through which, the viewpoints with high viewshed contribution are preserved and the number of viewpoints to be preserved can be controlled by the number of clusters. To evaluate the effectiveness of our CVF algorithm, we compare it with the Region Partitioning for Filtering (RPF) and Simulated Annealing (SA) algorithms. Experimental results show that our CVF algorithm is a substantial improvement in both computational efficiency and total viewshed coverage rate.     

"数字广州"空间数据基础设施建设策略研究

该文探讨了空间数据基础设施（SDI）在“数字城市”建设中的地位和作用,在此基础上,结合“数字广州”的要求和发展现状,指出了目前广州市空间数据基础设施建设存在的不足,并从政府管理的角度提出了加强空间数据基础设施建设的若干策略,涵盖了机构设置,数据政策,数据生产管理模式,人才培养和市场化等方面。     

Quantitative measuring and influencing mechanism of urban and rural land intensive use in China

Land use issue is an important constraining force to limit economic sustainable development of China. Urban and rural rapid expansion depletes valued land resources under the background of rapid urbanization. An extensive use pattern might cause a serious waste of land resources. The study on influencing mechanism of land intensive use （LIU） in China at the county level is a key tool for effective LIU practice and policy-making. This paper uses OLS model, Spatial Panel Lagged model and Spatial Panel Error model to quantitatively analyze the influencing mechanisms of five class factors and 17 variables supported by GIS （Geographic Information System） and MATLAB. And a comprehensive data set was devel- oped including physical geography and socio-economic information of 2286 counties. Meanwhile, the spatiotemporal pattern of LIU has discussed by means of GIS. The results show that Spatial Panel Data models are slightly superior to OLS model in terms of signifi- cance and confidence level. Regression results of these models indicate that industrialization, urbanization, economic development level, location, transportation and policy have significant impact on LIU of counties. The variables of physical geography are less significant than socio-economic variables. An ignored variable of historical factor, however, became the best significant factor. In the future, the LIU at the county level should take advantage of the new situation by enhancing favorable factors and reducing disadvantageous ones, which can be acquired by improving the entire level and quality of industrialization and urbanization. We argued that an efficient and complete land market and operating system should be built to reflect market-oriented activities at the first place, then, differential LIU regulation policies and measurements should be optimized according to regional differences. In the meantime, we should pay close attention to the carrying capacity of local resources and environments when conducting LIU practices.     

Local‐government data sharing: Evaluating the foundations of spatial data infrastructures

This paper presents a typology of local‐government data sharing arrangements in the US at a time when spatial data infrastructures (SDI) are moving into a second generation. In the first generation, the US National Spatial Data Infrastructure (NSDI) theoretically involved a pyramid of data integration resting on local‐government data sharing. Availability of local‐government data is the foundation for all SDI‐related data sharing in this model. However, first‐generation SDI data‐sharing activities and principles have gained only a tenuous hold in local governments. Some formalized data sharing occurs, but only infrequently in response to SDI programmes and policies. Previous research suggests that local‐government data sharing aligns with immediate organizational and practical concerns rather than state or national policies and programmes. We present research findings echoing extending these findings to show that local‐government data sharing is largely informal in nature and is undertaken to support existing governmental activities. NSDI principles remain simply irrelevant for the majority of surveyed local governments. The typology we present distinguishes four distinct types of local‐government data sharing arrangements that reflect institutional, political, and economic factors. The effectiveness of second generation, client‐service‐based SDI will be seriously constrained if the problems of local government take‐up fail to be addressed.     

Investigating the system dynamics technique for the modeling and simulation of the development of spatial data infrastructures

Spatial data infrastructure (SDI) is a complex system for which huge investments are being made worldwide. These large-scale investments in the development of SDIs incontrovertibly require reliable design and planning that guarantee a successful outcome. One approach to deal with such an expectation is to model the development process of the SDI system over time. If the model can be translated into the computer-based environment to be used as a virtual world, then the real situation can also be simulated. Such a simulation will enable the SDI coordinators/managers to gain knowledge about the behavior of the system under different decisions and situations and eventually help them to better develop the SDI through the informed decision making. However, a limited number of tools and techniques are currently available in the SDI modeling history in terms of the modeling and simulation of such a complex system. The system dynamics technique based on systems theory is a method for modeling and managing the feedback systems that are complex, dynamic and nonlinear over time. This article addresses the applicability of the system dynamics technique for modeling and simulating the development process of SDIs. It is argued that the system dynamics technique is capable of modeling the interactions among the factors affecting the SDI, the feedback loops and the delays. It is also highlighted that an SDI model based on the system dynamics technique enables the SDI coordinators/managers to simulate the effect of different factors or decisions on various aspects of SDI and evaluate alternative decisions and/or policies prior to making any commitment.     

中国城乡用地集约利用定量测度与影响机理(英文)

Land use issue is an important constraining force to limit economic sustainable development of China. Urban and rural rapid expansion depletes valued land resources under the background of rapid urbanization. An extensive use pattern might cause a serious waste of land resources. The study on influencing mechanism of land intensive use(LIU) in China at the county level is a key tool for effective LIU practice and policy-making. This paper uses OLS model, Spatial Panel Lagged model and Spatial Panel Error model to quantitatively analyze the influencing mechanisms of five class factors and 17 variables supported by GIS(Geographic Information System) and MATLAB. And a comprehensive data set was developed including physical geography and socio-economic information of 2286 counties. Meanwhile, the spatiotemporal pattern of LIU has discussed by means of GIS. The results show that Spatial Panel Data models are slightly superior to OLS model in terms of significance and confidence level. Regression results of these models indicate that industrialization, urbanization, economic development level, location, transportation and policy have significant impact on LIU of counties. The variables of physical geography are less significant than socio-economic variables. An ignored variable of historical factor, however, became the best significant factor. In the future, the LIU at the county level should take advantage of the new situation by enhancing favorable factors and reducing disadvantageous ones, which can be acquired by improving the entire level and quality of industrialization and urbanization. We argued that an efficient and complete land market and operating system should be built to reflect market-oriented activities at the first place, then, differential LIU regulation policies and measurements should be optimized according to regional differences. In the meantime, we should pay close attention to the carrying capacity of local resources and environments when conducting LIU practices.     

多源空间数据无缝集成研究

随着地理信息系统的社会化发展 ,空间数据共享成为一种必然要求 ,然而要真正实现空间数据共享 ,多格式空间数据集成是一个亟待解决的问题。多源空间数据无缝集成( SIMS)技术实现了一种特殊的数据访问机制 ,不仅提供了直接存取多种数据格式的能力 ,而且使 GIS软件具有跨数据源复合分析功能 ,是实现空间数据共享的有效的技术基础。本文阐述了 SIMS技术体系结构 ,并探讨了 SIMS技术在 GIS软件开发中的应用。     

地理信息系统在南极考察和研究中的应用

GIS在南极的应用包括空间数据采集和管理、测绘和制图、科学研究、环境保护、后勤管理和决策等各个方面。 SCAR的大地测量和地理信息工作组 (WG- GGI)每两年推出一批 GIS方面的国际合作项目 ,其中南极数字数据库 (ADD)、南极地理数据集成 (AGDI)、乔治王岛 GIS(KGIS)、空间数据标准等 GIS项目已取得显著成果 ,在南极研究领域产生了广泛的影响。本文介绍了国际上在南极开展的大量 GIS应用研究 ,为我国今后在该领域开展工作提供了参考与借鉴     

计算模式驱动下GIS体系结构的发展分析

计算模式是信息时代特有的解决问题的方法范式,它综合反映了信息科学的理论、软件与硬件等因素在解决实际问题中相互作用的形式,是与相应阶段主流信息技术相对应的信息系统体系结构的规律模式或构筑范式。该文分析了计算模式驱动下GIS的体系结构从单机模式、局域网模式、广域网模式(WebGIS)到网格模式(GridGIS)的发展过程,指出单机、局域网和广域网模式本质上都具有集中封闭的性质,不同程度地存在着理论、技术、物理、功能和逻辑思维等五大边缘,是典型的空间信息孤岛。网格计算模式是一种彻底的分布式计算模式,GIS的网格模式直接打破了传统模式的技术、物理、功能和逻辑思维限制,并面向理论边缘的解决,具有开放、均质、扁平的结构性质,升格为空间信息网格基础设施。     

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.     

Geo-portals as part of spatial data infrastructures: Russian Academy-supported resources and geoservices

Designing and implementation of the retrieval tools for shared spatial data as part of National Spatial Data Infrastructures (SDI) is among the top priorities of the preparatory stage of the long-term program envisaging the creation of the Russian SDI according to the concept of its creation and further development. This analytical overview of international experience defines the place and role of information resources accumulated in the Russian Academy of Sciences’ institutions during the last 15-year period of active development of geoinformation technologies in the context of spatial data acquisition and processing for geoscience applications. Based on some specific examples, it is shown that it is the Academy's science, even with its dramatic progression during this period, is the most prepared for the embodiment of the idea of integrating information and data using the SDI tools, and of ensuring broad, equitable and free access to them.     

“数字地球”的启示

本文分析了“数字地球”这一全球战略思想带给我们的一些启示 ,这些启示包括 :战略眼光 ,大国地位 ,自主发展和技术引进 ,盲目追随、整合的意义等。笔者认为 ,宏观的、全局性的战略眼光 ,冷静思考与明确的目标 ,紧抓对地观测和国家基础信息设施建设以维护中国作为大国的形象和利益 ,在发展“数字中国”过程中走自主发展与技术引进相结合的道路 ,以及加强行政管理机制、智能化数据、科研机构和学科领域的整合 ,是我们在数字地球的挑战面前应有的基本思路。     

不同流要素视角下沿海港口城市体系的网络空间联系

借助GIS、Matlab和Gephi等技术手段,运用不同流要素分析2006年和2016年中国沿海港口城市体系的网络联系及空间变化特征。结果表明：①在5个流动要素网络中,城市间的要素联系总量增加且增幅较大,集中分散程度、区域分布特征均发生了显著变化。港口城市体系的网络空间结构正由“点轴”模式向“网络化”模式转化。②不同流要素的枢纽城市具有高度重合性,但网络结构具有明显差异性。物流和客流呈现“组团发展”与“轴?辐”并存的网络特征。资金流和技术流发育出显著的“核心?边缘”和层次性的空间形态。信息流呈现均衡的网络化发展模式。③不同流要素刻画出不同层面的港口城市体系,但却有着紧密联系。物流与客流相互影响、互为因果。资金流和技术流对物流具有积极的促进作用。信息流对物流的影响具有明显的滞后性;港口城市体系由单一流要素转向多元流要素综合发展,港口城市间联系更加多元化,并实现了与外部流要素的互动融合。     

A spatial zoning approach to calibrate and validate urban growth models

Calibration and validation of models predicting urban growth have been largely developed using internal variables. Further investigation is required to improve model’s calibration and validation mixing internal and external variables. To reach this objective, a spatial zoning approach simulating long-term expansion of Mashhad, the second largest city of Iran, was presented in this study. Spatial zoning approaches distinguish local-scale urban dynamics in districts with different socioeconomic characteristics. Thiessen polygons were used to identify districts with different morphology and functional attributes. Urban growth was subsequently simulated for each district using a Multi-Layer Perceptron (MLP) neural network and Markov chains (MC) analysis. MLP and MC algorithms were respectively used to derive transition maps from non-urban to urban use of land and to determine spatial evolution of built-up areas at the metropolitan scale. Results of simulations based on spatial zoning were compared with outcomes of traditional urban growth models. Spatial zoning improved significantly model’s accuracy in respect to more traditional simulation modes. The approach proposed here is appropriate when simulating land-use changes under discontinuous urban expansion.