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1.
Many applications involving spatial data require several layers of information to be simultaneously analyzed in relation to underlying geography and topographic detail. This in turn generates a need for forms of multivariate analysis particularly oriented to spatial problems and designed to handle spatial structure and dependency both within and between spatially indexed multivariate responses. In this paper we focus on one group of such methods sometimes referred to as spatial factor analysis. Use of these techniques has so far been mostly restricted to applications in the geosciences and in some forms of image processing, but the methods have potential for wider use outside these fields. They are concerned with identifying components of a multivariate data set with a spatial covariance structure that predominantly acts over a particular spatial range or zone of influence. We review the various forms of spatial factor analysis that have been proposed and emphasize links between them and with the linear model of coregionalization employed in geostatistics. We then introduce extensions to such methods that may prove useful in exploratory spatial analysis, both generally and more specifically in the context of multivariate spatial prediction. Application of our proposed exploratory techniques is demonstrated on a small but illustrative geochemical data set involving multielement measurements from stream sediments. 相似文献
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A Spatial Analysis Neural Network (SANN) algorithm was applied for the analysis of geospatial data, on the basis of nonparametric statistical analysis and the concepts of traditional Artificial Neural Networks. SANN consists of a number of layers in which the neurons or nodes between layers are interconnected successively in a feed-forward direction. The Gaussian Kernel Function layer has several nodes, and each node has a transfer or an activation function that only responds (or activates) when the input pattern falls within its receptive field, which is defined by its smoothing parameter or width. The activation widths are functions of the model structural parameters, including the number of the nearest neighbor points P and a control factor F. The estimation method is based on two operational modes, namely, a training-validation mode in which the model structure is constructed and validated, and an interpolation mode. In this paper we discuss the effect of varying F and P upon the accuracy of the estimation in a two-dimensional domain for different input field sizes, using spatial data of wheat crop yield from Eastern Colorado. Crop yield is estimated as a function of the two-dimensional Cartesian coordinates (easting and northing). The results of the research led to the conclusion that optimal values of F and P depend on the sample size, i.e., for small data sets F=1.5 and P=7 while for large data sets F=2.5 and P=9. In addition, the accuracy of the interpolated field varies with the sample size. As expected for small sample sizes, the interpolated field and its variability may be significantly underestimated. 相似文献
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地质图空间数据库的建立是我国从纸制地质图件向多源地学空间信息数据库转变的一个标志,为多源地学信息综合分析和解释提供了充足的数据源。将建平幅以往大量的数据纸介质整理后进行属性数据、图形数据采集,建立了一个能够随意提取、可以不断更新的地质图件库,分析讨论了地质图数据库的特点、功能,并进行了应用。 相似文献
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基于证据权法构建滑坡地质灾害评价模型,进行杭州市滑坡地质灾害危险性区划研究。主要数据源包括1930－2009年杭州市域采集到的1 905个地质灾害个例以及杭州市地质图、土地利用数据及数字高程模型（DEM）等。利用Arcgis空间分析及信息提取功能,筛选强降水、地层岩性、坡度、坡向、坡高、河网与道路缓冲等证据因子,并运用证据权法客观确定各因子权重, 最后通过Arc-WofE扩展模块对多种优选因子的叠加,计算任意格网单元的滑坡发生概率,实现对潜在滑坡点位的空间预测。经分离样本法验证,区划准确率为88.3%,分析结果与现有滑坡的分布情况比较吻合。据此表明证据权法在多指标评价及其权重确定等方面具有普适性,值得在滑坡地质灾害危险性区划等方面推广应用。 相似文献
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中国地级及以上城市紧凑度的综合测度及其空间关联分析 总被引：2，自引：0，他引：2
从经济紧凑度、 土地利用紧凑度、 人口紧凑度和基础设施紧凑度等方面, 构建城市紧凑度的综合测度模型. 运用主成分分析法, 对2009年中国287个地级及以上城市紧凑度及其空间溢出效应进行综合测度. 结果表明: 紧凑度大致以"塔河-凭祥"一线为界, 以东区域的城市紧凑度水平较高, 以西的地区城市紧凑度水平低. 紧凑度Moran's I高值区连片集中在珠三角和长三角两个区域, 中心城市紧凑度的带动性和辐射性较强. 紧凑度呈现明显的热点-次热点-次冷点-冷点自东向西带状分布的格局. 经济发展、 土地利用结构和人口密度是目前中国地级以上城市紧凑度的重要决定因素, 城市土地利用因子表现相对较均衡, 而经济发展和人口密度两个主因子则表现出较强的不均衡性. 相似文献
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利用空间统计分析方法能够扩展和加强GIS的空间分析功能,从而更深入地探索、分析、处理和解释经济发展的空间模式与空间关联。将空间统计分析与GIS相结合,探索了江西省各县域经济的空间分布格局与规律。结果表明,江西省各县域经济存在显著的空间自相关和聚集模式,经济发展在空间上具有明显的规律。 相似文献
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Barry Boots 《GeoJournal》2001,53(4):339-345
8.
N. I. Fisher J. F. Huntington D. R. Jackett M. E. Willcox J. W. Creasey 《Mathematical Geology》1985,17(2):177-194
A frequently encountered problem in structural geology is the analysis and interpretation of directional data with a geographical distribution. Such data may arise, for example, as samples of fracture strikes collected at a number of locations (rocky outcrops, road cuttings, etc.), trends of geological structures mapped in underground mines where they are exposed in the tunnel roof, or as lineaments annotated on aerial or satellite photographs. From such data, it is of interest to determine the structural domains in the area, that is, to partition the area into subareas of homogeneous structural pattern. This paper presents a method for performing such an analysis, and applies it to a data set collected from an underground coal mine. 相似文献
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在现存地下水监测网站中,观测站点分布的任意性、随意性和层次不清以及观测数据的冗余性等问题普遍存在,应用空间聚类原理,对所选研究区域廊坊地下水的监测点位及监测指标分别进行了空间聚类分析,对原始数据和经聚类处理后的数据分别进行了空间变异性评价,结果显示空间聚类分析是有效合理的。试图将空间变异性和空间聚类方法结合起来,为环境监测点的重新布置提供了理论依据,使提高监测效率与监测点的代表性、优化监测网格成为了可能;了解监测指标及监测点位在空间上的相关程度,为环境监测指标的确定提供理论依据,进而为环境管理、污染物控制以及环境资源的综合利用提供基础依据。 相似文献
10.
Yukio Sadahiro 《GeoJournal》2000,52(3):237-252
The present paper proposes a new method for analyzing the spatial structure of retailing, using microscale locational data
of individual retail stores. The method is based on the probability density function (PDF) of stores estimated from their
locational data, and consequently it is applicable to both micro- and macro-scale retail analyses. The PDF approach provides
a set of quantitative methods that permit us (1) to measure the degree of agglomeration, (2) to classify spatial patterns
of store location, (3) to analyze the relationship between the size and function of retail agglomerations, and (4) to analyze
the spatial structure of retail agglomeration. An empirical study is performed to test the validity of the method, and some
empirical findings are shown.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
Fractals and the accuracy of geographical measures 总被引：20，自引：0，他引：20
Michael F. Goodchild 《Mathematical Geology》1980,12(2):85-98
The problems of estimating line length, area, and point characteristics in the earth sciences have generated substantial but independent literatures. All three problems are of increasing concern given the current interest in digital capture, processing, and the storage of geographically referenced data. In the case of qualitative maps, all three are shown to be related to Mandelbrot's fractional dimension D (Mandelbrot, 1977) which allows the dependence of each on sampling density to be predicted. The general results are confirmed by simulation on surfaces of constant D. They also imply that certain improvements can be made in a number of previously proposed methods. 相似文献
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Te Xiao Zi-Jun Cao Xiao-Song Tang 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2017,11(1):146-159
ABSTRACTA simplified reliability analysis method is proposed for efficient full probabilistic design of soil slopes in spatially variable soils. The soil slope is viewed as a series system comprised of numerous potential slip surfaces and the spatial variability of soil properties is modelled by the spatial averaging technique along potential slip surfaces. The proposed approach not only provides sufficiently accurate reliability estimates of slope stability, but also significantly improves the computational efficiency of soil slope design in comparison with simulation-based full probabilistic design. It is found that the spatial variability has considerable effects on the optimal slope design. 相似文献
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利用空间计量模型对上海市镇域2009年建设用地规模与经济社会发展之间的关系进行了研究。研究表明：上海镇域的建设用地面积、GDP、固定资产投资额、总人口和城市化率都有显著的空间相关特征,说明传统计量分析低估了区域社会经济发展对建设用地增长的作用,也忽略了一个区域经济社会发展对邻近区域的建设用地的增长的“溢出效应”,忽略空间相关性和异质性的传统估计模型已不再适用,须考虑引入空间变量对传统模型进行修正。空间误差模型检验表明,建设用地扩张主要受GDP和人口增长的驱动,其中总人口的影响更为显著,而固定资产投资和城市化水平提高对建设用地规模影响甚微。因此,合理把握人口增长节奏,促进农村建设用地集约水平提高,是当前缓解土地资源紧缺的有效途径之一。 相似文献
15.
Traditionally, urban analysis has been quick to adopt and benefit from developments in technology (e.g., microcomputer, GIS) and techniques (e.g., statistics, mathematical programming). This has not been the case, however, with newer methods of spatial analysis — in particular, spatial statistics. Only recently has this situation started to change. This paper documents the confluence of spatial statistics and urban analysis by first reviewing developments in spatial statistics, and then presenting examples of recent applications in urban analysis. The developments reviewed fall under the rubric of global and local forms of spatial analysis, and cover three major technical issues: spatial association, spatial heterogeneity and the modifiable areal unit problem. The examples highlight the relevance and usefulness of the techniques reviewed for urban transportation and land-use applications. The paper concludes with conjectures concerning future developments at the intersection of spatial statistics and urban analysis. 相似文献
16.
Traditionally, urban analysis has been quick to adopt and benefit from developments in technology (e.g., microcomputer, GIS) and techniques (e.g., statistics, mathematical programming). This has not been the case, however, with newer methods of spatial analysis — in particular, spatial statistics. Only recently has this situation started to change. This paper documents the confluence of spatial statistics and urban analysis by first reviewing developments in spatial statistics, and then presenting examples of recent applications in urban analysis. The developments reviewed fall under the rubric of global and local forms of spatial analysis, and cover three major technical issues: spatial association, spatial heterogeneity and the modifiable areal unit problem. The examples highlight the relevance and usefulness of the techniques reviewed for urban transportation and land-use applications. The paper concludes with conjectures concerning future developments at the intersection of spatial statistics and urban analysis. 相似文献
17.
在我国北方干旱－半干旱区，以过去气候变化记录为主线，探讨了地质环境的变化过程及其分析方法；在时间尺度上，通过综合研究分别在青藏高原、黄土高原和华北平原建立了概念化的高分辨率气候指标(温度、降水)演化过程曲线，作为分区的特征演化曲线；在空间尺度上，对研究较深入的现代和全新世最佳期(７５００ａＢ．Ｐ．前后)、１８０００ａＢ。Ｐ．前后的冷期等时段的地质环境状况进行重建；利用空间分析计算机软件，对典型时段的地质环境状况进行连续空间分析，进而由分区特征演化曲线与典型时段地质环境空间分布模型耦合。这一分析对认识我国北方干旱－半干旱区今后的环境变化是十分有益的。 相似文献
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The spatial arrangement of sedimentary rock components is a fundamental property of sedimentary rocks. If we assume that the size, shape, and composition of sedimentary rock components (mineral grains, pores) carry useful petrologic information, there is no reason to assume that their spatial arrangement does not. Spatial arrangement has been discussed in terms of texture and fabric, but it has had little objective measurement or classification. This deficiency is primarily due to the difficulties associated with the quantification of spatial phenomena. However, using digital-imaging techniques it is possible to generate petrographic images from thin-sections and quantify the spatial arrangement of selected rock components using a two-dimensional (2D) Fourier transform. A Fourier transform creates a spectral representation of the image similar to an x-ray diffraction pattern. This paper presents the fundamental framework of 2D Fourier analysis in petrology. This type of analysis provides a means to quantify and analyze the spatial arrangement of rock components in an objective, mathematical framework. 2D Fourier power spectra can be used to characterize the type and degree of spatial order in an image, both in terms of the classical concepts of long-range and short-range order and in terms of spatial patterns characteristic of sedimentary rock. The clearly defined mathematical relationship between an image and its Fourier power spectrum provide the opportunity to define the 2D structure of an image in the same manner that x-ray diffraction patterns are used to map 3D structure in minerals. In addition, a 2D Fourier power spectrum is easily transformed into a radial power spectrum. Radial power spectra can be used to characterize the density of objects in an image. They also provide a valid means to compare and contrast images in a multivariate framework, regardless of the type of order. One of the most desirable properties of a Fourier transform is its reversibility. Using selected components of the power spectrum, the inverse transform can be used to build synthetic images, which highlight those petrologic components that most affect the power spectrum. The inverse transform provides the means to translate the results of analysis into meaningful petrologic characteristics. 相似文献