地理表达研究进展

地理表达是地理学的一个基本问题,也是地理信息科学研究面临的一个重大挑战.从地理表达机理、内容和形式的角度,对近期地理表达研究进行了总结.本质上,地理表达是一个空间认知、信息转换与信息传输的交互过程.地理表达内容涉及地理实体及其空间关系、不确定性、地理动态及地理本体等方面.地理表达形式经历了从自然语言、地图到GIS的演变...     

西非海洋渔业资源非法捕捞现状和对策

海洋渔业(尤其是小型海洋渔业)为世界各地的沿海居民提供了重要的食物来源、就业、经济收入。西非临近海域是世界上海洋渔业资源最丰富的地区之一,在西非沿海地区数百万居民以捕鱼为生,然而,西非众多捕鱼区却是最贫穷的地区。在全球化不断推进的今天,非法捕捞已严重威胁到海洋生态系统安全。西非临近海域的非法捕捞问题尤为严峻。在整合相关文献资料的基础上,分析了非法捕捞的主要影响,并对西非地区的非法捕捞现状和问题进行了讨论,认为部分欧盟国家是非洲西部海洋渔业资源主要非法捕捞者,西方学者认为中国是西非地区主要的非法捕捞者是不符合事实的。非法捕捞的根本原因是持续的鱼类需求和捕捞活动缺乏控制。基于以上分析,提出了西非非法捕捞的应对措施,以期有助于解决西非非法捕捞问题。     

An SVG-based method to support spatial analysis in XML/GML/SVG-based WebGIS

XML/GML/SVG-based approaches are promising for building Web-based geographic information systems (WebGIS). However, current XML/GML/SVG-based WebGISs are lacking in spatial analysis. Some of them are designed for web mapping only. Others adopt a server-side solution for spatial analysis, which suffers from the ‘bottleneck’ problem and results in a high network transmission load. Load-balancing spatial analysis between server side and browser side can be used to solve the above problems. This article focuses on one of the key building blocks of load-balancing spatial analysis, that is, SVG-based spatial analysis which enables spatial querying and analysis directly on SVG (on the browser side). After analyzing the workflow of spatial analysis, we identify and focus on two key issues in providing spatial analysis on SVG: SVG-based spatial information representation and SVG-based spatial extended structured query language (SSESQL). For the first issue, a theoretical foundation is set up to develop an SVG-based spatial information representation model. Some spatial operators are designed and integrated into an SSESQL to support spatial querying on SVG. Finally, we design and implement two case studies. The results of these case studies show that the proposed method is feasible and operable in supporting spatial analysis directly on SVG on the browser side. The proposed method can be easily incorporated with some existing methods (e.g., GML-based spatial analysis on the server side) to provide load-balancing spatial analysis (load balancing between server side and browser side) in XML/GML/SVG-based WebGIS. As a result, users can access high-performance spatial analysis simply via a web browser (such as Internet Explorer and Firefox).     

Multi-criteria modelling and clustering of spatial information

To improve the formal integration of verbally given spatial information in a geographical information system, a methodology for converting such information to a geographical representation was developed. This was applied to examples of a spatial-related analysis of natural language text messages in the domain of disaster management. This article presents an approach for such a conversion by using a suitable knowledge representation as well as formal modelling structures. The structures are provided by an ontology-supported knowledge base. With respect to spatial uncertainty, a formal representation based on possibility theory was defined. Moreover, a cluster algorithm was developed for handling information of different sources and building a spatial context.     

An object-oriented knowledge representation structure for exploration data integration

Knowledge representation structure and reasoning processes are very important issues in the knowledge-based approach of integrating multiple spatial data sets for resource exploration. An object-oriented knowledge representation structure and corresponding reasoning processes are formulated and tested in this research on the knowledge-based approach of integrating spatial exploration data. The map-based prototype expert system developed in this study has self-contained knowledge representation structure and inference mechanisms. It is important to distinguish between lack of information and information providing negative evidence for a map-based system because the spatial distribution of data sets are uneven in most cases. Error and uncertainty estimation is also an important component of any production expert system. The uncertainty propagation mechanisms developed here work well for this type of integrated exploration problem. Evidential bellef function theory provides a natural theoretical basis for representing and integrating spatially uneven geophysical and geological information. The prototype system is tested using real mineral exploration data sets from the Snow Lake area, northern Manitoba, Canada. The test results outline the favorable exploration areas successfully and show the effectiveness of the knowledge representation structure and inference mechanisms for the knowledge-based approach.     

Ontologies and representation spaces for sketch map interpretation

In this paper, we present a systematic approach to sketch map interpretation. The method decomposes the elements of a sketch map into a hierarchy of categories, from the material sketch map level to the non-material representational sketch map level, and then interprets the sketch map using the five formal representation spaces that we develop. These spaces (set, graph, metric and Euclidean) provide a tiered formal representation based on standard mathematical structures. We take the view that a sketch map bears information about the physical world and systematises this using extensions of existing formal ontologies. The motivation for this work is the partially automatic extraction and integration of information from sketch maps. We propose a set of ontologies and methods as a first step in the direction of a formalisation of partially automatic extraction and integration of sketch map content. We also see this work as a contribution to spatial cognition, where researchers externalise spatial knowledge using sketch mapping. The paper concludes by working through an example that demonstrates the sketch map interpretation at different levels using the underlying method.     

基于场所的GIS中的不确定性问题及分类框架

基于场所的GIS直接表达人类地理空间知识的管理和加工过程,而不确定性是人类智能的基本特点,因此GIS的智能化需要研究其中的不确定性问题。与传统的GIS相比,基于场所的GIS中的不确定性问题更为丰富,既包括随机性,也包括含糊性,而不确定性的主体既可以是地理要素、场所和空间关系,也包括命题和规则。该文介绍该领域相关的研究成果,基于不确定性主体、类型、表达手段及相关的活动4个视角,建立了基于场所的GIS中所涉及的不确定性框架,从而为相关的不确定性建模提供指导。     

Fishing in a congested sea: What do marine protected areas imply for the future of the Maltese artisanal fleet?

Inshore artisanal fishing in Malta is under intense spatial competition as the coastal zone is fragmented by multiple uses and designations including maritime transport, infrastructure, industrial fisheries, aquaculture, tourism and recreation. This research, adopting a grounded visualization methodology, explains how the artisanal fishing sector has undergone and been affected by ‘spatial squeezing’. Our results show that artisanal fishermen have been forced to give up fishing grounds or co-exist with other uses to the point where the ability to fish is becoming increasingly challenging. These difficulties might escalate with the advent of the marine protected areas (MPAs) which encompass nearly half of the inshore fishing zones. Since there does not seem to be effective MPA consultation mechanisms that elicit the real social, cultural and economic value of artisanal fishing grounds, fishermen feel threatened, alienated and disempowered. This study urges for a more holistic approach to spatial marine planning and accentuates the need of realizing the dependency of the artisanal sector on the inshore zones in the implementation of conservation measures, such that the prolonged existence of the coastal fishing communities is not jeopardized.     

环境信息科学可视化表达与交互研究

灵活的科学可视化表达与交互手段能有效地展示隐藏在数据背后的空间特性及空间关系.在分析科学可视化概念和特点的基础上,探讨其在动态环境信息表达、环境信息可视化交互探索分析方面的应用,并以江苏省城市空气质量评价专题为例,采用ArcGIS Server基础平台,利用rich internet application(RIA)技术,对Web环境下环境信息的科学可视化进行实例研究.     

Temporal Point Pattern Analysis of Human Activities Using GIS Methods: A Case Study of Library Visiting Activities in Chengdu City,China

This article aims to develop a new type of temporal pattern analysis—temporal point pattern analysis (TPPA)—by treating the distribution of activities as a point pattern on a two-dimensional plane using the start time and end time of activities as axes. Geographic information systems (GIS) methods, which are originally used in spatial point pattern analysis in GIS, are introduced to support TPPA. This article presents a case study to understand the temporal patterns of the library visiting activities of university students using a four-week smart card data set in Chengdu City, China. Several methods from GIS are applied, including the measurement of mean centers, kernel density, nearest neighbor distances, and optimized hot spot analysis. Results show that the GIS methods can reveal a lot of information on the temporal pattern of activities, thereby proving the reasonability of the proposed TPPA of activities. Key Words: GIS, human activities, library visiting, smart card data, visualization.     

Mixed methods participatory GIS: An evaluation of the validity of qualitative and quantitative mapping methods

Participatory mapping in social research is characterized by methodological pluralism, with two common methods being qualitative mapping using stakeholder interviews and quantitative methods that engage larger public samples through digital, internet mapping. To date, there has been no systematic evaluation of the extent to which mixed methods in participatory mapping yield valid results when applied to the same research setting and research questions. A mixed methods research design (combined exploratory sequential and convergent parallel) was implemented in a large research project to identify marine and coastal values in the Kimberley region of Australia. Qualitative interviews (n = 167) were completed with stakeholders to identify place-based values using polygon mapping methods and internet-based public participation GIS (PPGIS) methods (n = 578). We defined and operationalized the concepts of concurrent, commensurate, and convergent validity to assess mixed methods research outcomes. We found that qualitative and quantitative methods resulted in moderate to high concurrent validity when assessing the importance of place values in the study area. Convergent validity (spatial) was highly variable by place value, with stronger convergent validity found with mapped aesthetic, recreational fishing, tourism, biodiversity, and Aboriginal culture values, and weakest with existence, therapeutic, and commercial fishing values. Convergent validity was influenced by weak commensurate validity through the use of different geometric features (polygons versus points) for mapping values across a large study area. The utility of mixed methods for planning decision support in a convergent parallel design depends on demonstrating convergence in construct meaning, spatial location, and consistency in values in the sampling populations.     

Multidimensional visualisation of degrees of relevance of geographic data

The ever‐increasing number of spatial data sets accessible through spatial data clearinghouses continues to make geographic information retrieval and spatial data discovery major challenges. Such challenges have been addressed in the discipline of Information Retrieval through ranking of data according to inferred degrees of relevance. Spatial data, however, present an additional challenge as they are characteristically made up of geometry, attribute and, optionally, temporal components. As these components are mutually independent of one another, this paper suggests that they be ranked independently of one another. The representation of the results of the independent ranking of these three components of spatial data suggests that representation of the results of the ranking process requires an alternative approach to currently used textual ranked lists: visualisation of relevance in a three‐dimensional visualisation environment. To illustrate the possible application of such an approach, a prototype browser is presented.     

A formal framework for the representation of stack-based terrains

This paper presents a formal framework for the representation of three-dimensional geospatial data and the definition of common geographic information system (GIS) spatial operations. We use the compact stack-based representation of terrains (SBRT) in order to model geological volumetric data, both at the surface and subsurface levels, thus preventing the large storage requirements of regular voxel models. The main contribution of this paper is fitting the SBRT into the geo-atom theory in a seamless way, providing it with a sound formal geographic foundation. In addition we have defined a set of common spatial operations on this representation using the tools provided by map algebra. More complex geoprocessing operations or geophysical simulations using the SBRT as representation can be implemented as a composition of these fundamental operations. Finally a data model and an implementation extending the coverage concept provided by the Geography Markup Language standard are suggested. Geoscientists and GIS professionals can take advantage of this model to exchange and reuse geoinformation within a well-specified framework.     

信息时代高铁走廊区域居民活动空间——概念模型与研究框架

作为中国最重要的城市与区域基础设施,信息技术和高速铁路正加速影响居民的行为活动,传统的活动空间已发生转型,而以高流动性为基本特点的信息时代高铁走廊区域活动空间逐渐形成。这一背景下,活动空间研究亟需立足信息与交通技术前沿,探究新时期活动空间的基本形态与研究范式。通过构建信息时代高铁走廊区域活动空间的概念模型,分析了活动空间的构成与形成机理,并从空间性质、尺度、形态、结构等方面提炼了活动空间的新特征。在此基础上提出新时期活动空间的研究框架,即构建以流动空间为基本的理论出发点,利用多元数据融合、集成分析的创新方法探索居民行为活动与区域空间要素的相互作用、影响机制及其空间效应的研究框架。这对于活动空间研究体系的丰富和深化、实证研究的开展以及高铁走廊区域的统筹规划具有重要意义。     

Evaluating representation and scale error in the maximal covering location problem using GIS and intelligent areal interpolation

A common problem in location-allocation modeling is the error associated with the representation and scale of demand. Numerous researchers have investigated aggregation errors associated with using different scaled data, and more recently, error associated with the geographic representation of model objects has also been studied. For covering problems, the validity of using polygon centroid representations of demand has been questioned by researchers, but the alternative has been to assume that demand is uniformly distributed within areal units. The spatial heterogeneity of demand within areal units thus has been modeled using one of two extremes – demand is completely concentrated at one location or demand is uniformly distributed. This article proposes using intelligent areal interpolation and geographic information systems to model the spatial heterogeneity of demand within spatial units when solving the maximal covering location problem. The results are compared against representations that assume demand is either concentrated at centroids or uniformly distributed. Using measures of scale and representation error, preliminary results from the test study indicate that for smaller scale data, representation has a substantial impact on model error whereas at larger scales, model error is not that different for the alternative representations of the distribution of demand within areal units.     

基于GIS和AIS的渤海海上船舶活动时空特征分析

基于2018年海上船舶自动识别系统(Automatic Identification System, AIS)数据,借助GIS空间分析方法,对渤海海上船舶位置及密度、船舶速度等空间分布特征以及船舶流量日、月和季节变化的时间特征进行分析,得到以下结论：① 渔业船舶多活动于近岸海域,呈团聚状分布;商业船舶多聚集在公共航道区,整体呈带状分布;货船数量占商业船舶总量的78.58%,主要为中型货船,客船与油轮以中小型船舶所占比重相对较大。② 渤海船舶速度以中低速为主,尤其是渔业船舶;较高速度的船舶主要是大中型货船和客船。③ 渔业船舶活动时间和季节变化特征显著,秋季休渔期结束后以及白天工作时间段渔船活动较频繁;与渔业船舶相比,渤海商业船舶活动受季节变化和昼夜交替影响较小。分析发现,渤海交通流密度高,船舶会遇频繁,发生船舶碰撞以及重大污染事故的风险较大;东西向和南北向的海上交通与渔业捕捞作业船舶之间存在较大的海域空间利用冲突,需要引起足够的重视。自然环境与资源条件、沿岸社会经济发展与港口建设、海域管制等因素影响海上船舶时空分布。     

基于场所的GIS研究

探讨从地理空间认知出发,实现基于场所的GIS（PB—GIS）的相关问题。PB—GIS以场所为核心,显式表达地理空间知识,并遵循特定规则进行定性空间推理,从而服务于空间行为决策。比较PB—GIS与基于坐标的GIS（CB—GIS）之间的差异和适合解决的问题,并描述定性空间推理的特点及其在PB—GIS中的应用。在分析实现PB—GIS的关键技术基础上,采用三层架构设计了一个PB-GIS的概念体系结构。     

Spatial representation of economic and financial measures used in agriculture via wavelet analysis

A foundation is set forth for use of the wavelet transform as a spatial analysis tool for modelling the geographical representation of economic and financial measures used in agriculture. This provides a framework from which to estimate a smooth nonparametric function which describes complex, multivariate relationships embedded in spatial data, with the resulting maps conveying large amounts of information in a familiar format. We illustrate this approach for tasks which include the graphical presentation of information, density estimation and wavelet-based nonparametric regression. A redundant wavelet transform is used, and we detail the properties which make it particularly appropriate for these objectives.