地理信息科学中尺度问题的30年研究现状

尺度在地学中无处不在,地理信息科学也不例外。自Abler 1987年将尺度列为地理信息的几个重要科学问题之一,30年来,各国学者为尺度问题做了大量的研究工作。试图对这30年的研究作一简单的回顾,明析已解决的部分问题和尚需进一步努力的方向。讨论的重点是Goodchild等提出的5大关键问题,即尺度不变量、改变尺度的能力、尺度效应的度量、尺度作为过程模型中的参数及多尺度方法的实施。通过讨论发现,尺度效应得到了很好的研究,但主要是针对数据尺度,多种尺度（如数据尺度和分析尺度）的联合效应研究仍然严重贫乏;现在有很多转换模型可供使用,但是有些方法的理论基础不够完美;"尺度作为过程模型中的参数"这一问题最任重道远;尺度变换引起的信息量变化缺乏系统研究。这些问题需要引起高度的重视。     

地理信息科学基础理论的思考

目前人们对地理信息科学基础理论的认识尚未达到完全统一.从地理学、测绘学和信息学理论视角凝炼出地理空间和时空基准、空间认知、地理信息传输过程、地理信息计算机表达、空间数据可视化与尺度、尺度分级规律以及地理数据不确定性等理论作为地理信息科学的基础理论,旨在引起国内学者对地理信息科学理论问题的探讨和思考,关注地理信息科学基础理论研究,推动地理信息科学的发展.     

GIS中多尺度地理数据库的研究与应用

文中首先分析了ＧＩＳ中建立多心谋理数据库的必要性,然后介绍了多尺度地理数据库的建立方法,并提出了一种混合表示法的设计、实现和更新方法,最后讨论了应用多尺度地理数据库方法建立港城市地理信息系统的实例。     

从横向上的“一张图”到纵向上的“金字塔”：地理国情数据的多尺度表达

地理国情普查成果描述了自然地表和人文地理要素的空间分布、特征及其相互关系,在制定和实施国家战略发展与规划、优化国土空间开发格局、优化各类资源配置工作中发挥着重要作用。为了从全局观念、系统性整体化应用好该普查成果,成果管理部门在横向上建立了“一张图工程”,通过空间数据库技术将地理国情调查成果全覆盖、无重叠、无缝隙地展示。然而,为了面向不同级别行政部门管理、不同层次行业部门应用、不同详略信息数据提取,成果表达还应进一步在纵向上构建多级“金字塔式”数据组织,灵活有效地为不同应用需求输出合适级别的成果数据,金字塔结构不同层次数据对应不同水准的应用需求,同时跨层次间的数据联系反映了同一区域的地理国情状况在不同视图下的表达。本文系统地讨论地理国情普查成果构建金字塔式数据表达的技术方法,涉及众源大数据处理、地图综合与尺度变换、多级瓦片地图架构、跨层次级联更新等技术的应用。     

地理信息科学方法论案例研究

作为上期论文的续篇,本文针对地理信息六种科学方法中的四种和七种技术方法中的四种进行了案例研究。其中图形/图像思维方法的案例是纵向岭谷区通道-阻隔理论的形成和北部湾M型战略的建立;数学模型方法的案例是区域生态环境评价模型和区域突发公共事件应急反应模型;地学信息图谱方法的案例是黄土高原地貌形态图谱在在土地利用中的应用;智能分析与计算方法的案例是旅游出行辅助决策分析和县级农业对弈决策分析;地理信息采集和监测技术方法的案例是森林火灾自动监测与报警系统;地理信息表达技术方法的案例是中国资源环境电子地图集;地理信息服务技术方法的案例是基于CNG I的可持续发展信息服务系统;地理信息网格技术方法的案例是基于中国国家网格的陆面数据同化系统。总之,通过案例研究,丰富了地理信息科学方法论的理论和范式,对于地理信息科学本身的发展也有益处。     

地理数据库驱动的地图表达机制研究

当前GIS系统生产出来的地图产品在制图学家眼里缺乏说服力。GIS软件完成地图符号化后,地图产品的最后阶段将不得不脱离GIS数据库而在出版软件中完成,从而中断了工作流程,割裂了地理要素与地图对象的联系,难以进行地图的更新。本文提出了基于GIS的地图表达机制,在GIS中融入地图制图功能,既便于地理数据库驱动下的地图制图,又便于地图的增量更新。     

地理信息科学专业“地图投影”课程教学改革与实践

文章通过分析地理信息科学专业的特点,结合中国矿业大学地理信息科学专业"地图投影"课程教学改革,从教学内容的选取、教学方法的选择、考核方式的改革三个方面论述了地图投影教学与改革的方法。结合专业特点选择教学内容,注重动手能力的培养,强调互动教学与直观教学,结果表明,通过教学改革,激发了学生学习的主动性,提高了学习的兴趣性,教学效果良好。     

基于关键比例尺的空间数据多尺度表达

已有的空间数据多尺度表达多为基于静态多版本机制的.其原理是通过不同的系列比例尺数据之间的尺度变换来模拟地理要素的连续显示,这在地图缩放过程中给用户视觉上造成了较强的跳跃感.这里在相邻的基础比例尺数据之间插入中间比例尺(关键比例尺)数据来进行空间数据的多尺度表达,给用户连续的视觉感受.     

空间数据连续尺度表达的矢量金字塔模型

连续多尺度表达是当前地图制图领域中的热点问题之一,常规地图采用多级瓦片剖分、多版本存储技术实现空间多尺度表达,存在数据量冗余、跨级别不一致、瓦片间尺度跳跃大等问题。结合传统地图综合、多尺度表达数据结构和空间索引建立等多种策略,在目标数据模型中加入尺度维和操作信息,记录地图综合的过程和尺度变换,建立空间数据矢量金字塔模型。该模型离线综合获取多级基态尺度表达数据,确定每个目标的尺度表达空间范围,并通过面向对象建模技术将目标表达状态及其纵向关联关系、算子类型及控制参量等信息封装在多尺度目标中;同时,建立一端或两端控制的尺度变换结构。基于该模型可快速获取适应用户需求的连续尺度表达状态。     

地理信息科学专业高水平师资队伍建设的探索与实践

师资队伍是一流专业建设与一流人才培养的关键因素,也是推进我国高校有组织科研的实施者。本文以中南大学地理信息科学专业为例,探讨了行业特色“双一流”高校高水平师资队伍建设的影响因素与实施途径,并分析了近年来师资队伍建设的成效与问题。本文对地理信息科学专业师资队伍建设的实施策略和途径,可为相关院校地理信息科学一流专业建设与人才培养质量提升提供参考。     

Embedding scale: new thinking of scale in machine learning and geographic representation

Journal of Geographical Systems - Concepts of scale are at the heart of diverse scientific endeavors that seek to understand processes and how observations and analyses influence our understanding....     

中小比例尺下居民地综合及冲突处理

针对中小比例尺地形图上的散列式居民地较难进行自动化综合缩编的问题,该文对中小比例尺地形图上散列式居民地的综合过程及其冲突处理方法进行了研究。首先,通过探测邻近关系和分析空间特征,对居民地进行合并和选取,减少目标数,控制数量变化;进一步地通过模板匹配对单一的目标进行形状化简,控制表达变化。同时,针对其综合处理和符号化过程中可能出现的空间冲突,提出了基于Delaunay三角网模型的探测和处理方法。最后,给出了一套中小比例尺地形图上居民地要素的综合处理策略。该研究成果可规模化应用于中小比例尺综合缩编生产实践。     

多尺度表达中空间拓扑关系等价性评价模型

本文主要讨论不同尺度下地理目标之间拓扑关系的等价性问题。根据人类认知习惯,得出从大比例尺地理空间中拓扑关系抽象为小比例尺空间中拓扑关系应当遵循的基本规则,并利用模糊函数将这些规则定量化;在此基础上,得到评价地理空间场景中多个空间目标之间拓扑关系在不同尺度下是否等价的综合评价模型。该模型可以用于检验和维护空间数据质量、为地图自动综合提供空间关系处理和评价方法的参考。     

双坐标系组合图在地球信息图谱化中的应用

文章选择新颖的斜角坐标系量化图形中的双坐标系组合图形用于展现地球信息图谱。通过筛选多种多样的组合形式选择适合于不同地球信息展示的最佳图形样式,高效、美观地传递信息,使地球复杂系统的统计数据中蕴藏的时空规律跃然纸上,为研究地学信息图谱引进了一种新的表达方法。     

Spatial representation in the social interaction potential metric: an analysis of scale and parameter sensitivity

The social interaction potential (SIP) metric measures urban structural constraints on social interaction opportunities of a metropolitan region based on the time geographic concept of joint accessibility. Previous implementations of the metric used an interaction surface based on census tracts and the locations of their centroids. This has been shown to be a shortcoming, as the metric strongly depends on the scale of the zoning system in the region, making it difficult to compare the SIP metric between metropolitan regions. This research explores the role of spatial representation in the SIP metric and identifies a suitable grid-based representation that allows for comparison between regions while retaining cost-effectiveness with respect to computational burden. We also report on findings from an extensive sensitivity analysis investigating the SIP metric’s input parameters such as a travel flow congestion factor and the length of the allowable time budget for social activities. The results provide new insights on the role of the modifiable areal unit problem in the computation of time geographic measures of accessibility.     

基于滚动球变换的TIN_DDM地形形态划分及连续尺度表达

针对TIN_DDM地形形态划分及连续尺度表达中存在的应用场景与数据类型特殊、地形形态划分边界不明确和地形尺度认知存在差异等问题,提出了一种基于滚动球变换的TIN_DDM地形形态划分及连续尺度表达算法。该算法在分析滚动球变换构建原理的基础上,通过挖掘滚动球变换在地形形态识别方面的应用潜能,设计了TIN_DDM采样点地形类型判定准则;针对判定准则在地形形态连续尺度表达过程中无法应用的问题,通过对滚动球接触点与滚动球半径之间的数值关联性进行分析,求解出各采样点与滚动球接触状态变换时的临界滚动球半径,构建了面向TIN_DDM地形形态连续尺度表达的滚动球变换。试验结果表明:该算法可快速实现以滚动球半径作为尺度因子的TIN_DDM地形形态自动化分及连续尺度表达。     

An integrated wavelet concept of physical geodesy

For the determination of the earth's gravity field many types of observations are nowadays available, including terrestrial gravimetry, airborne gravimetry, satellite-to-satellite tracking, satellite gradio-metry, etc. The mathematical connection between these observables on the one hand and gravity field and shape of the earth on the other is called the integrated concept of physical geodesy. In this paper harmonic wavelets are introduced by which the gravitational part of the gravity field can be approximated progressively better and better, reflecting an increasing flow of observations. An integrated concept of physical geodesy in terms of harmonic wavelets is presented. Essential tools for approximation are integration formulas relating an integral over an internal sphere to suitable linear combinations of observation functionals, i.e. linear functionals representing the geodetic observables. A scale discrete version of multiresolution is described for approximating the gravitational potential outside and on the earth's surface. Furthermore, an exact fully discrete wavelet approximation is developed for the case of band-limited wavelets. A method for combined global outer harmonic and local harmonic wavelet modelling is proposed corresponding to realistic earth's models. As examples, the role of wavelets is discussed for the classical Stokes problem, the oblique derivative problem, satellite-to-satellite tracking, satellite gravity gradiometry and combined satellite-to-satellite tracking and gradiometry. Received: 28 February 1997 / Accepted: 17 November 1997     

An integrated representation of spatial and temporal relationships between evolving regions

 The study of relationships between evolving regions within GIS still needs the development of operators that integrate the spatial and temporal dimensions. This paper introduces a new approach that combines topological relationships between regions in 2-dimensional space with temporal relationships between convex intervals in time. Resulting relationships are defined and visually presented within a 3-dimensional space that integrates the geographical space as a 2-dimensional space and the time line as the third dimension. Conceptual neighbourhoods are identified and extended by the concept of semi-transitions and transitions. Such a flexible framework presents the advantage of being derived from accepted relationships in both space and time. Its computational implementation is therefore compatible with current spatial and temporal GIS models. Received: May 2000 / Accepted: June 2001     

An efficient representation of quadtrees and bintrees for multiresolution terrain models

A space-filling curve in 2,3,or higher dimensions can be thought as a path of a continuously moving point.As its main goal is to preserve spatial proximity,this type of curves has been widely used in the design and implementation of spatial data structures and nearest neighbor-finding techniques.This paper is essentially focused on the efficient representation of Digital Ele-vation Models(DEM) that entirely fit into the main memory.We propose a new hierarchical quadtree-like data structure to be built over domains of unrestricted size,and a representation of a quadtree and a binary triangles tree by means of the Hilbert and the Sierpinski space-filling curves,respectively,taking into account the hierarchical nature and the clustering properties of this kind of curves.Some triangulation schemes are described for the space-filling-curves-based approaches to efficiently visualize multiresolu-tion surfaces.     

应用空间技术研究干旱和半干旱地区由盐化作用造成的土地退化(英文)

This study applied a computerized parametric methodology to monitor, map, and quantify land degradation by salinization risk detection techniques at a 1：250 000 mapping scale using geo-information technology. The northern part of the Shaanxi province in China was taken as a case. Multi-temporal remotely sensed materials of both Landsat TM and thematic maps （ETM＋） were used as the bases to provide comprehensive views of surface conditions such as vegetation cover and salinization detection. With ERDAS ver. 9.1 software, the Normalized Differential Salinity Index （NDSl） and Salinity Index （S.I.） were computed and then evaluated for land degradation by salinization. Arc/Info ver. 9.2 software was used along with field observation data （GPS） for analysis. Using spatial analysis methods, results showed that 19 973.1 km^2 （72%） of land had no risk of land degradation by salinization, 3 684.7 km^2 （13%） had slight land degradation by salinization risk, 2 797.9 km^2 （10%） had moderate land degradation by salinization risk, and 1 218.9 km^2 （4%） of the total land area was at a high risk of land degradation by salinization. The study area, in general, is exposed to a high risk of soil salinization.