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621.
郑春燕 《测绘与空间地理信息》2006,29(4):28-31
根据地貌晕渲基本理论和技术,利用Arc/Info制作了彩色晕渲图,并探讨了不同参数下的晕渲效果,最后还尝试了将晕渲图加载到表面视图,以从不同的角度来观察地貌形态。 相似文献
622.
桐柏-信阳一带区域地球化学调查是全国区域化探扫面的一部分.编图中涉及19和20投影带及个1:20万图幅的拼接,制图中存在不少技术难题.为了避免2个投影带产生的裂隙坐标不统一,将20带数据转换到19带,然后在高斯-克吕格座标表中查取座标自然值,并计算座标通用值后进行座标展绘,取得了较好的制图效果. 相似文献
623.
Data interpretation is one of the most important and thorny tasks in geosciences. Difficulties occur especially in non-invasive geophysical techniques and/or when the data that have to be analyzed are multidimensional, non-linear and highly noisy. Another important task is to ensure an efficient automatic data analysis, in order to allow a data interpretation as independent as possible from any a priori knowledge. This paper describes the post-processing application of a kind of neural network (self-organizing map, SOM) to the identification of the fundamental HVSR frequency of a given site. SOM results can be represented as two-dimensional maps, with a non-parametric mapping that projects the high dimensional original dataset in a fashion that provides both an unsupervised clustering and a highly visual representation of the data relationships. This innovative application of the SOM algorithm is presented with a case study related to the characterization of a mineral deposit. 相似文献
624.
Predictive models for calculating sediment yield and discharge require accurate areal data. Such models may be unrealistic when using digitized data given the potential error involved in compiling and digitizing thematic polygon maps. The estimation of boundary variability for digitized polygon maps of a 0·34 km2 area of badlands in Dinosaur Provincial Park, Alberta shows the effects of positional errors introduced during mapping and digitizing processes. Polygon overlay of maps of surface features and slopes produced high frequencies of very small polygons and some unlikely combinations of slopes and surface features, and decreased reliability in areal measurements in the composite map. At an epsilon band width of 0·7 m, a reasonable estimate of boundary variability, 31·7 per cent of the resultant overlaid map can be considered unreliable. 相似文献
625.
建筑群震害响应模拟是现代城市震害防御管理工作的基础。高效的建筑信息获取方法与科学合理的建筑群动力响应分析模型建模方法是快速、准确震害模拟的前提,也是震害防御科学管理、迅速决策和精准施策的必要保障。本文提出利用GIS平台进行矢量地图数据采集、多图层空间叠加分析及地形分析;结合我国各地市政府数据开放平台,获取建筑使用功能、建成年代、结构类型及场地类别等基本信息;在此基础上建立一套基于真实城市信息的建筑群动力响应分析模型建模方法。该方法操作简便、模型精度高并且建模速度快,可实现城市区域大规模建筑群高效建模。针对成都市某街区建筑群进行数据采集和模型建立,验证了该方法的可行性和有效性。 相似文献
626.
627.
As large destructive seismic events are not frequent in Algeria, anexhaustive knowledge of the historical seismicity is required to have arealistic view of seismic hazard in this part of the world. This research workpresents a critical reappraisal of seismicity in the north-eastern Algeria forseismotectonic and seismic hazard purposes. This part of work focuses onthe seismicity of pre-1900 period for the area under consideration[33°N-38°N, 4°E-9.5°E]. By going back tothe available documentary sources and evaluating and analysing the eventsin geographical, cultural and historical context, it has been possible toidentify 111 events, from 1850–1899, which are not reported in therecent Algerian catalogue. Several spurious events, reported in standardlistings, have been deleted and nine unknown events have been discovered.It is quite clear that macroseismic information derived from press reportsand published documents in Algeria, under certain conditions, is veryincomplete, even for destructive earthquakes, located in the countrysideaway from communication centres. One of the reasons for this iscensorship, noticeable during the colonisation period. Critical analysis ofnewly collected information has allowed the determination and/or theimprovement of the macroseismic parameters of each event, such aslocation, maximum epicentral intensity and magnitude to produce anearthquake catalogue as homogeneous and complete as the available data,for the zone under study. The criteria used in this research are explainedand eight historical earthquakes have been the subject of retrospectivemacroseismic field construction.The investigation of historical earthquakes is one of the most important taskin studying seismotectonic for seismic hazard evaluation purposes. 相似文献
628.
ZHANG Jingxiong Roger P.Kirby 《地球空间信息科学学报》2000,3(2):26-34
1 IntroductionCategoricalmapsrepresentanimportanttypeofdataincorporatedinGISs,whichdepictspatialdis tributionsinformofexhaustive,non_overlappingarealunitsseparatedbyboundarylines.Anassump tionunderlyingconventionalcategoricalmappingistheobject_basedview… 相似文献
629.
In recent years, the visualization of geospatial data has undergone dramatic and important developments. Next to static maps, nowadays, immersive and highly interactive virtual environments can be used to explore and present dynamic geospatial data. Additionally, the World Wide Web has developed into a prominent medium to disseminate geospatial data and maps. In visualizing geospatial data, methods and techniques from fields, such as scientific visualization and information visualization, are applied because of the large volumes of data at hand. This has accumulated in what is known as geovisualization—the use of visual geospatial displays to explore data and through that exploration to generate hypotheses, develop problem solutions and construct knowledge. Maps and other linked graphics play a key role in this process. The objective of this paper is to demonstrate the usefulness of geovisualization and, in particular, how alternative graphic representations can stimulate the visual thought process. This is demonstrated by applying geovisualization techniques to Minard's well-known map of Napoleon's 1812 campaign into Russia, the “Carte figurative des pertes successives en hommes de l'Armee Française dans la campagne de Russie 1812–1813” (http://www.itc.nl/personal/kraak/1812/). 相似文献
630.