Voronoi生成的Clifford代数实现方法

引入具有维度融合、坐标无关等特性的Clifford几何代数,构建不同维度统一Voronoi生成框架及算法流程。定义了可支撑不同维度、不同对象间距离、相交及对偶关系的几何、拓扑运算,基于多重向量设计了可支撑不同维度地理对象的统一存储结构及关系表达机制,实现了基于Clifford代数的多维统一Voronoi生成算法。以中国城市气象数据为例进行了算法验证,并分析了算法复杂度。结果表明,该算法可根据输入数据维度自适应地实现相应维度的Voronoi分析,可为以维度统一为特征的GIS分析算法实现提供借鉴。     

GIS支持下山区县域农村居民点分布特征研究——以栖霞市为例

运用GIS空间分析技术、景观指数法和Voronoi图Cv值相结合的分析方法,研究了胶东山区栖霞市农村居民点的空间均匀性特征,并探讨了农村居民点在地形梯度上的分布特征。结果表明:全市农村居民点分布的Cv值为58.84%,空间分布表现为随机分布;唐家泊镇、松山镇、臧家庄镇和翠屏街道4个乡镇的农村居民点呈集群分布,其他乡镇为随机分布;农村居民点分布的优势区间在1~3地形位,随着地形位的增大农村居民点的优势度降低;农村居民点的面积、斑块数目和平均斑块面积随地形位的增大而减少,平均斑块形状指数和平均斑块分维数随地形位的增大而增大;同时,公路是影响山区农村居民点空间布局的重要因素。研究反映了栖霞市农村居民居住习惯的差异,为农村居民点的整治和规划提供了依据。     

格氏栲天然林土壤有机碳空间分布及其影响因素

采用GIS技术对格氏栲天然林土壤有机碳空间分布特征及其影响因素进行研究,结果表明:土壤有机碳含量(O)、土壤有机碳密度、土壤有机碳储量均属于中等变异,且随土层深度的增加而减少,表层富集现象明显.土壤有机碳含量在Ⅰ层(0 ～ 20 cm)为32.15 g/kg,分别是Ⅱ层(20～40 cm)、Ⅲ层(40 ～ 60 cm)的2.35、4.63倍,剖面均值为17.60 g/kg;土壤有机碳密度在Ⅰ～Ⅲ层分别为6.76 kg/m2、3.17 kg/m2、1.74 kg/m2,土壤剖面平均有机碳密度为11.67 kg/m2.引入泰森多边形替代土壤类型图,计算得格氏栲天然林土壤有机碳储量为1.49×104 t,Ⅰ层、Ⅱ层、Ⅲ层分别为8.66×103 t、4.01 × 103 t、2.20×103 t.土壤有机碳含量和土壤有机碳密度空间分布情况类似:在西南和东北各有一个高值区,以WS - EN为中线,西北和东南呈近似对称的条带状分布,且向两边表现出递减的趋势.相关分析和逐步回归分析表明,土壤有机碳含量与土壤理化性质相关性均达到极显著水平,与全氮(TN)、全磷(TP)、水解性氮(AN)、有效磷(AP)、速效钾(AK)显著正相关,与全钾(TK)、pH、土壤容重(B)显著负相关,满足O=38.19+72.42 TN+0.04AN+54.47 TP - 7.50pH - 7.04B.同时分析了地形、土壤理化性质、人为活动等对格氏栲天然林土壤有机碳含量的影响.研究结果可为提高土壤有机碳储量精度、评估格氏栲天然林生态效益及其在区域碳循环中的作用和功能提供参考依据.     

西藏捌仟措盐湖卤水等温蒸发试验研究

以西藏捌仟措盐湖卤水为研究对象,依据Na+,K+,Mg2+//Cl-,SO24--H2O五元水盐体系相图,对该盐湖卤水进行了5℃等温蒸发试验,研究了卤水蒸发过程中盐类析出规律和钾、锂和硼在蒸发过程中的富集行为,为该盐湖卤水盐田规划设计、现场生产操作提供了依据。     

Jacques Bertin,from classical training to systematic thinking of graphic signs

ABSTRACT

Nearly 50 years after the publication of the first French edition of Sémiologie Graphique, Jacques Bertin’s thought is more than ever alive, in cartography as well as in various other disciplines, such as graphic design or visual data analysis. This article recalls the main elements of Bertin’s career and puts forward the salient points of his reflection on graphics. Beyond many conceptual or technical innovations, Bertin’s essential originality appears to be his attempt to propose a general framework for graphical representations.     

Reply to “Comments on Climatology: The Challenge for the Eighties Revisited”

Book reviews in this article

The Heated Debate: Greenhouse Predictions Versus Climate Reality. ROBERT C. BALLING JR. San Francisco: Pacific Research Institute for Public Policy, 1992. xxxvi and 195 pp., diags., tables, index, and biblio. $21.95 cloth (ISBN 0-936488-47-6).

Mountain Weather and Climate, 2nd edition. ROGER G. BARRY. New York: Routledge, Chapman and Hall, 1992. xx and 402 pp., maps. diags., photos, index, and biblio. $89.95 cloth (ISBN 0-415-07112-7); $29.95 paper (ISBN 0-415-07113-5).

Late Quaternary Environmental Change: Physical and Human Perspectives. MARTIN BELL and MICHAEL J. C. WALKER. Essex, England: Longman Group, 1992. xiv and 273 pp., maps, diags., index, and biblio. $39.95 paper (ISBN 0-582-04514-2).

Planning for Earthquakes. PHILIP R. BERKE and TIMOTHY BEATLEY. Baltimore: The Johns Hopkins University Press, 1992. xv and 210 pp., maps, diags., photos, tables, app., acronyms, index, and biblio. $38.00 cloth (ISBN 0-8018-4255-7).

Industrialization and Development in the Third World. RAJESH CHANDRA. London: Routledge, 1992. xvii and 124 pp., maps, figs., photos, and index. $14.95 paper (ISBN 0-415-01380-1).

Waste Location: Spatial Aspects of Waste Management, Hazards and Disposal. MICHAEL CLARK, DENIS SMITH, and ANDREW BLOWERS, eds. London: Routledge, 1992. xv and 257 pp., maps, diags., index, and refs. $85.00 cloth (ISBN 0-415-04824-9).

Water Diversion and Export: Learning from Canadian Experience. J. C. DAY and FRANK QUINN. Waterloo, Ontario: Department of Geography, University of Waterloo, 1992. xx and 215 pp., 14 maps, 4 diags., 17 tables, 12 photos, glossary, and biblio. $25.00 (Can.) paper (ISBN 0-921083-42-4).

The Native Population of the Americas in 1492, 2nd edition. WILLIAM M. DENEVAN, ed. Madison: The University of Wisconsin Press, 1992. xxxviii and 353 pp., maps, figs., tables, index, biblio. $45.00 cloth (ISBN 0-299-134-30-X); $14.95 paper (ISBN 0-299-13434-2).

Touring North America (series). ANTHONY R. DE SOUZA, ed. New Brunswick: Rutgers University Press, 1992. 13 volumes; pages varying from approximately 100 to approximately 300 each; maps, diags., indices, and biblios. $9.95 each paperback; $25.00 each volume in cloth; boxed gift set of all 13 volumes in paperback $129.95. (ISBNs for cloth and paperback editions range from 0-8135-1870-9 to 0-8135-1895-4 inclusive).

Urban Transport Planning: A Developmental Approach. HARRY T. DIMITRIOU. New York: Routledge, 1992. xviii and 346 pp., diags., index, and biblio. $92.50 cloth (ISBN 0-415-03857-X).

Colonialism and Development in the Contemporary World. CHRIS DIXON and MICHAEL HEFFERNAN, eds. Rutherford, NJ: Mansell, 1991. viii and 232 pp., maps, diags., index, and biblio. $70.00 cloth (ISBN 0-7201-2072-1).

The Betweenness of Place: Towards a Geography of Modernity. J. NICHOLAS ENTRIKIN. Baltimore: The Johns Hopkins University Press, 1991. xii and 196 pp., notes, and indices. $38.50 cloth (ISBN 0-8018-4083-X); $13.95 paper (ISBN 0-8018-4084-8).

The Women Outside: Meanings and Myths of Homelessness. STEPHANIE GOLDEN. Berkeley: University of California Press, 1992. ix and 265 pp., index and biblio. $25.00 cloth (ISBN 0-520-07158-1).

The Transformation of Agriculture in the West. DAVID GRIGG. Oxford, England, and Cambridge, MA: Basil Blackwell, 1992. xiv and 141 pp., maps, diags., index, and biblio. $19.95 paper (ISBN 0-631-17094-4).

Derelict Landscapes: The Wasting of America's Built Environment. JOHN A. JAKLE and DAVID WILSON. Savage, MD: Rowman and Littlefield, 1992. xviii and 342 pp., illus., index, biblio. $65.00 cloth (ISBN 0-8476-7735-4); $23.50 paper (ISBN 0-8476-7736-2).

Iranian Cities: Formation and Development. MASOUD KHEIRABADI. Austin: University of Texas Press, 1991. xiv and 132 pp., maps, diags., photos, appendices, notes, glossary, biblio., and index. $27.50 cloth (ISBN 0-292-72468-3).

The Pentagon and the Cities. ANDREW KIRBY, ed. Newbury Park, CA: Sage Publications, 1991. Urban Affairs Annual Reviews, vol. 40. x and 207 pp., tables, maps, index, and biblio. $43.95 cloth (ISBN 0-8039-3845-4); $19.95 paper (ISBN 0-8039-3846-2).

Geographic Perspectives on Soviet Central Asia. ROBERT A. LEWIS, ed. London and New York: Routledge, 1992. xv and 323 pp., maps, diags., index, and biblio. $69.95 cloth (ISBN 0-415-07592-0).

Conquest and Survival in Colonial Guatemala: A Historical Geography of the Cuchumatan Highlands, 1500–1821. W. GEORGE LOVELL. Montreal and Kingston: McGill-Queen's University Press, 1992. xxxviii and 279 pp., maps, diags., glossary, notes, index, and biblio. $19.95 paper (ISBN 0-7735-0903-8).

Contested Lands: Conflict and Compromise in New Jersey's Pine Barrens. ROBERT J. MASON. Philadelphia: Temple University Press, 1992. xii and 257 pp., maps, tables, index, and biblio. $44.95 cloth (ISBN 0-87722-925-2).

Making Sense of Place: Children's Understanding of Large-Scale Environments. M. H. MATTHEWS. Savage, MD: Harvester Wheatsheaf, Barnes and Noble Books, 1992. xiv and 271 pp., maps, diags, tables, index, and biblio. $54.50 cloth (ISBN 0-389-20987-2).

Sources of Metropolitan Growth. EDWIN S. MILLS and JOHN F. MCDONALD, eds. New Brunswick: Center for Urban Policy Research Press, 1992. xxvii and 306 pp., maps, diags., index, and biblio. $29.95 cloth (ISBN 0-88285-135-7).

Resource Management in Developing Countries. PETER H. OMARAOJUNGU. Harlow, England: Longman, 1992. xvi and 213 pp., maps, diags., tables, index, and biblio. $39.95 paper (ISBN 0-582-30102-5).

A Moveable Shore: The Fate of the Connecticut Coast. PETER C. PATTON and JAMES M. KENT. Durham: Duke University Press, 1992. viii and 143 pp., maps, diags., index, and biblio. $49.95 cloth (ISBN 0-8223-1128-3); $19.95 paper (ISBN 0-8223-1147-X).

Agricultural Reform in China: From Communes to Commodity Economy 1978–1990. SIMON G. POWELL. Manchester, England: Manchester University Press, 1992. viii and 231 pp., maps, diags., tables, and biblio. $69.95 cloth (ISBN 0-7190-3382-9).

The Caribbean in the Wider World, 1492–1992: A Regional Geography. BONHAM C. RICHARDSON. Cambridge: Cambridge University Press, 1992. xvi and 235 pp., maps, tables, index, and biblio. $49.95 cloth (ISBN 0-521-35186-3); $16.95 paper (ISBN 0-521-35977-5).

Scavengers, Recyclers, and Solutions for Solid Waste Management in Indonesia. DANIEL T. SICULAR. Berkeley: Center for Southeast Asian Studies, University of California at Berkeley, 1992. xii and 197 pp., maps, tables, photos, glossary, biblio., and index. $16.50 paper (ISBN 0-944613-13-6).

The Sphinx in the City: Urban Life, the Control of Disorder, and Women. ELIZABETH WILSON. Berkeley: University of California Press, 1992. 191 pp., plates, index, and biblio. $35.00 cloth (ISBN 0-520-07850); $14.00 paper (ISBN 0-520-07864-0).

The Cultural Geography of the United States: A Revised Edition. WILBUR ZELINSKY. Englewood Cliffs: Prentice Hall, Inc., 1992. ix and 226 pp., maps, diags., index, and biblio. $21.95 paper (ISBN 0-13-194424-X).     

Modelling three‐dimensional geoscientific fields with the Voronoi diagram and its dual

Fields as found in the geosciences have properties that are not usually found in other disciplines: the phenomena studied are often three‐dimensional (3D), they tend to change continuously over time, and the collection of samples to study the phenomena is problematic, which often results in highly anisotropic distributions of samples. In the geographical information system (GIS) community, raster structures (voxels or octrees) are the most popular solutions, but, as we show in this paper, they have shortcomings for modelling and analysing 3D geoscientific fields. As an alternative to using rasters, we propose a new spatial model based on the Voronoi diagram (VD) and its dual the Delaunay tetrahedralisation (DT), and argue that they have many advantages over other tessellations. We discuss the main properties of the 3D VD/DT, present some GIS operations that are greatly simplified when the VD/DT is used, and, to analyse two or more fields, we also present a variant of the map algebra framework where all the operations are performed directly on VDs. The usefulness of this Voronoi‐based spatial model is demonstrated with a series of potential applications.     

基于Voronoi图的点状要素注记自动配置

对点状要素候选注记位置质量进行了量化评定,提出了基于Voronoi图的点状要素注记自动配置的思想,并对其进行了实验性验证,理论及实验分析结果表明此种方法逻辑严密,简单易行,注记配置速度快、回溯次数少,超常规注记配置出现个数少,对GIS平台点状要素注记自动配置具有指导意义。     

紧急救援下障碍空间分析技术的应用

灾害紧急救援提出了对地理信息技术新的急迫要求：即动态GIS中的动态数据模型和“0”初始化计算问题障碍空间路径规划问题、“安全岛”问题——障碍空间最大（小）间隙问题、与安全区的k阶邻近问题,本文给出了这些问题的解决途径和解算实例。     

基于气象监测网络的森林火险快速预警模型

森林火灾发生频繁且突发性强,进行森林火险快速预警对于减小森林火灾损失和促进森林资源可持续发展至关重要。本文基于GIS空间分析和可视化技术,利用地面气象站构建实时气象监测网络,设计了运用气象监测网络的森林火险预警模型,可实现森林火险及时、快速预警。模型应用层次分析法建立了预警因子重要性层次结构并确定预警因子的权重;运用Voronoi图技术,基于气象站点和实时气象数据,构建气象监测网络;利用叠置分析技术计算得出预警结果。基于该模型设计的森林火灾快速预警系统应用于青海省林业局,验证了系统可行性与适用性,该模型可全面、准确、快速地实现对森林火险的预警。结果表明：① 根据预警模型及实时气象监测数据,可及时发出预警信号,快速实现县级、林场级别的森林火险早期预警和及时响应;② 运用GIS可视化技术,可快速生成相关区域森林火险的空间分布专题图,直观地观察预警等级的变化情况。实践表明,森林火险快速预警对森林火灾进行有效预防、中断管理和制定扑救措施具有重要的指导作用,并对森林防火工作、保护森林资源和人类生命财产安全具有重大意义。