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301.
A quantitative procedure for analyzing and comparing distortion in mental maps is presented. Using a microcomputer and digitizer, and by developing a distortion index, comparisons are made by direct analysis of mental maps. A case study of the mental maps of Israel of high school and university students showed a tendency to generalize shape to simple geometric forms, with foreshortening of north-south lines and exaggeration of east-west distances. 相似文献
302.
Geographic research has not focused on the information we encode into our memories about the characteristics of locations. The accuracy of information encoded in urban cognitive maps, how information varies among individuals, and the structure of the information were studied. Experimental results indicated subjects were more accurate and consistent for socio-economic than for life-cycle characteristics. Some characteristics of the population in a neighborhood, such as race and income, may be more visible and easier to encode through direct contact than other less visible characteristics such as age. A theoretical argument is made that characteristics not encoded for locations can possibly be computed through their covariation with known characteristics. 相似文献
303.
Aristoteles Vergara Muñoz 《Natural Hazards》1991,4(1):1-6
Probabilistic seismic hazard maps in term of Modified Mercalli (MM) intensity are derived by applying the Cornell-McGuire method to four earthquake source zones in Panama and adjacent areas. The maps contain estimates of the maximum MM intensity for return periods of 5, 25 and 100 yr. The earthquake phenomenon is based on the point source model. The probabilistic iso-intensity map for a return period of 50 yr indicates that the Panama Suture Zone (PSZ) could experience a maximum (MM) intensity IX, and the Panama Fracture Zone (PFZ) an MM intensity VIII, for the rest of the area this varies from IV up to VIII. The present study intends to serve as a reference for more advanced approaches, to stimulate discussions and suggestions on the data base, assumptions and inputs, and path for the risk based assessment of the seismic hazard in the site selection and in the design of common buildings and engineering. 相似文献
304.
模糊类别制图的空间统计学方法 总被引:4,自引:1,他引:3
类别地图是地理信息系统(GIS)应用中所利用的重要数据类别。这类数据可以从摄影测量和遥感技术得到。用摄影测量方法(影像判读)制作的类别地图常以点、线和多边形的离散目标形式描述,而遥感图像分类方法输出的类别地图以连通光栅块形式表达。不论哪一种情况,在每一个多边形或者光栅块(即制图单元)中仅允许单一类别,边界内部非均匀性和模糊形已经被“过滤”了。这样的类别地图沿用了古曲脆集合论,因为每个制图单元只允许 相似文献
305.
Giorgio Rivalenti Maurizio Mazzucchelli Vicente Antonio Vitorio Girardi Giancarlo Cavazzini Cristina Finatti Maria Adelaide Barbieri Wilson Teixeira 《Lithos》1998,43(4):235-265
Paleoproterozoic basaltic, andesitic and rhyolitic dykes crosscut the Archaean Carajás basement. Basalts are distinguished into a high and a low TiO2 group (HTi and LTi), each group consisting of geochemically distinct NE- and NW-trending swarms. The HTi dykes are evolved transitional basalts having essentially EMORB-type geochemistry. The LTi basalts are tholeiites (NE-trending swarm) and high-Al basalts (NW-trending swarm) displaying incompatible trace elements patterns with variably negative Nb anomaly, enrichment in Rb, Ba, K (LILE) and La, Ce and Nd (LREE) and positive Sr anomaly. With respect to orogenic analogues, andesites have lower Al2O3, CaO and Ni, higher FeO, LILE, LREE, Nb, Zr and Ti and negative Sr anomaly. Rhyolites have geochemical characteristics comparable with those of A-type granites. At 1.8 Ga,
ranges from 0.700 to 0.705 in the HTi basalts and from 0.700 to 0.704 in the LTi group. Andesites define an isochron of 1874±110 Ma (Sro=0.7038±0.0010). Rhyolites from Southern and Northern Carajás define two isochrons of 1802±130 Ma (Sro=0.7062±0.0046) and 1535±82 Ga (Sro=0.7625) respectively, the younger date being interpreted as resetting of the Rb–Sr isotopic system. We propose a petrogenetic model relating LTi basalts with melting of lithospheric mantle metasomatized by acid melts derived from incipient melting of eclogites, representing in turn the subsolidus product of basaltic batches trapped in the mantle. The HTi basalts are explained by melting of the lithospheric mantle containing the complementary residual eclogite. Andesite petrogenesis is consistent with crystal fractionation from a high-Mg andesite parent derived from a mantle source more extensively metasomatized by eclogite-derived melts. Rhyolite composition is consistent with low melting degree of the basement rocks. The basalt–andesite–rhyolite dykes may represent the effects of crustal extension and arching in Carajás, which produced the anorogenic acid to intermediate magmatism (Uatumã group) and affecting a large part of the Amazon craton between 1.85 and 1.7 Ga. 相似文献
306.
Boundaries between the various topographic, geologic, and socio-political entities that span the Earths continental surfaces are determined by a myriad of complexly interrelated natural and/or cultural factors. Areas of large river basins, of lithologic units on geologic maps, and of nations exhibit size frequency distributions that are closely approximated by density functions in which diameters of individual areas are distributed exponentially. As such, size distributions of each type of surface unit are closely modeled as randomly delimited areas. In other words, if one were to walk in a straight line across any particular continent, each step along that transect would embody some random continuous probability of passing out of a major drainage basin, or out of an area of more or less homogeneous rock type, or from one country to another. Moreover, this simple truism gives rise to area frequency distributions for large river basin or outcrop or nation area that are primarily dependent on the number of basins or outcrops or countries that exist across that particular landmass. As a consequence, the size frequencies of these areal units can be closely predicted knowing only the total area under consideration and the number of drainage basins, outcrop areas, or nations that exist within the area. The similarity between area frequencies of large river basins and rock types and nations suggests a nontrivial component of geologic influence on the partitioning of continental surfaces into major political divisions, and implies that cultural and economic factors, which serve to divide and unite political entities, do so within a geological framework. 相似文献
307.
海南岛小海沙坝-泻湖-潮汐通道体系自动调整及恶化 总被引:5,自引:0,他引:5
本文运用历史地图对比方法,结合现场考察及水文泥沙测量资料,分析海南岛小海口门近40a来的变化过程,找出小海口门在人为作用下的演变规律.结果表明,小海沙坝—泻湖—潮汐通道体系曾是一个稳定的系统,它通过口门断面、地形调整以适应在人类活动作用下口门动力的变化并保持相对平衡.三大人为活动的综合影响,尤其是盐墩三岛的围垦及冈箱养殖,破坏了口门维持的最后动力(潮汐动力),使小海沙坝—泻湖—潮汐通道体系失去了调整作用,直接导致了口门的迅速缩小.因此小海综合治理的首要任务是小海口门的治理。 相似文献
308.
In this paper, we publish the results of a bathymetry survey based on the processing of satellite altimetry data. Data gathered from GEOSAT (Geodetic Mission), SEASAT, ERS-1 and TOPEX/POSEIDON satellites were processed to recover the seafloor topography over new seamounts in a test area located in the south central Pacific. We show that by processing high-density satellite altimetry data, alone or in combination with shiptrack bathymetric data, it is possible to produce full coverage bathymetric maps. 相似文献
309.
Václav Čada 《The Cartographic journal》2017,54(2):126-138
310.
Since 2012 CORINE has been obtained in Spain from the generalization of a more detailed land cover map (SIOSE). This methodological change has meant the production of a new CORINE map, which is different from the existing ones. To analyze how different the new maps are from the previous ones, as well as the advantages and disadvantages of the new methodology, we carried out a comparison of the CORINE obtained from both methods (traditional and generalization) for the year 2006. The new CORINE is more detailed and it is more coherent with the rest of Spanish Land Use Land Cover (LULC) maps. However, problems have been encountered with regard to the meaning of its classes, the fragmentation of patches and the complexity of its perimeters. 相似文献