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1.
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
2.
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
3.
空间数据：性质、影响和分析方法 总被引：22，自引：1，他引：21
20世纪90年代以来,以信息技术为主要标志的科学进步日新月异,正深刻地改变着人类社会的生产和生活方式。人类活动所涉及的信息80％以上属空间信息,可由地理坐标确定其空间区位,美国已将发展空间信息科学视为提升其国家竞争力水平的重要途径之一。2000年美国国家地理信息与分析中心（Nat ionalCenterforGeo graphicInformat ionandAnalysis,NCGIA）在其跨世纪的研究规划中提出了发展地理信息科学的Varenius计划。Varenius计划要求研究空间信息的不确定性理论,并开发处理这种不确定性的空间数据分析技术。鉴于空间数据的两维多方向性,空间数据所包含的误差远比单一方向性的时间序列数据来得复杂。最近发展起来的空间统计学和空间计量经济学不仅解决了标准统计方法在处理空间数据时的失误问题,更重要的是为测量这种空间联系及其性质、并在建模时明确地引入空间联系变量以估算与检验其贡献提供了全新的手段。基于美国地理信息科学的发展动态,重点阐释空间统计学和空间计量经济学的理论基础,包括空间数据的性质、空间信息的误差理论、空间数据分析的类型和内容。 相似文献
4.
More recently, driven by rapid and unguided urbanisation and climate change, Ghanaian cities are increasingly becoming hotspots for severe flood-related events. This paper reviews urbanisation dynamics in Ghanaian cities, and maps flood hazard zones and access to flood relief services in Kumasi, drawing insight from multi-criteria analysis and spatial network analysis using ArcGIS 10.2. Findings indicate that flood hazard zones in Kumasi have been created by natural (e.g., climate change) and anthropogenic (e.g., urbanisation) factors, and the interaction thereof. While one would have expected the natural factors to guide, direct and steer the patterns of urban development from flood hazard zones, the GIS analysis shows that anthropogenic factors, particularly urbanisation, are increasingly concentrating population and physical structures in areas liable to flooding in the urban environment. This situation is compounded by rapid land cover/use changes and widespread haphazard development across the city. Regrettably, findings show that urban residents living in flood hazard zones in Kumasi are also geographically disadvantaged in terms of access to emergency services compared to those living in well-planned neighbourhoods. 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
7.
Narushige Shiode 《GeoJournal》2000,52(3):263-269
This paper reports on recent developments in the visualisation of urban landscapes. There is a growing interest in the contstruction
of 3D models of urban and built environment for which a host of digital mapping and rendering techniques are being developed.
This paper extracts some of the cases that we came across during worldwide interviews carried out in March 2000. Building
on this review, we identify the range of data and techniques adopted for the development of 3D contents and how they could
contribute to geographical analysis and planning of urban environment. A particular focus is given on the effectiveness of
GIS and its related methods for their capacity to accommodate the demands for visual representation of urban environment as
well as the basis for analysis and simulation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Validation Techniques for Geological Patterns Simulations Based on Variogram and Multiple-Point Statistics 总被引：2，自引：2，他引：0
Traditional simulation methods that are based on some form of kriging are not sensitive to the presence of strings of connectivity
of low or high values. They are particularly inappropriate in many earth sciences applications, where the geological structures
to be simulated are curvilinear. In such cases, techniques allowing the reproduction of multiple-point statistics are required.
The aim of this paper is to point out the advantages of integrating such multiple-statistics in a model in order to allow
shape reproduction, as well as heterogeneity structures, of complex geological patterns to emerge. A comparison between a
traditional variogram-based simulation algorithm, such as the sequential indicator simulation, and a multiple-point statistics
algorithm (e.g., the single normal equation simulation) is presented. In particular, it is shown that the spatial distribution
of limestone with meandering channels in Lecce, Italy is better reproduced by using the latter algorithm. The strengths of
this study are, first, the use of a training image that is not a fluvial system and, more importantly, the quantitative comparison
between the two algorithms. The paper focuses on different metrics that facilitate the comparison of the methods used for
limestone spatial distribution simulation: both objective measures of similarity of facies realizations and high-order spatial
cumulants based on different third- and fourth-order spatial templates are considered. 相似文献
9.
基于多源多时相数据集的喀什市近70a城区空间扩展遥感研究 总被引：2，自引：1，他引：1
使用民国34年（1945年）1∶1×104地形图、1968年CORONA影像及近期Landsat5和2015年GE影像数据,使用遥感技术以多元多时相遥感数据融合和GIS挖掘技术为支撑,采用等扇分析法和重心转移矩阵分析了喀什市70a城市空间形态整体扩展特征,各方向上的扩展速度、强度以及空间重心转移的方向、强度。结果表明：1945-2015年间喀什市空间形态经历了带状扩展向团状扩展的转变,城市整体空间扩展强度不断加剧,空间扩展速度呈先上升后下降再上升的趋势,空间重心向东南方向绿洲腹地转移1009m,侵占甚多绿洲耕地,城市空间扩展模式粗放,亟待调整。 相似文献
10.
Kathrin Häb Nils H. Feige Lars S. Huettenberger Ariane Middel Hans Hagen 《Environmental Earth Sciences》2014,72(10):3781-3793
In urban microclimate research, ground-based thermography is used to gain insight into the spatial distribution of surface temperatures of various materials. Taking snapshots over a certain time span helps experts to observe the temporal thermo-radiative behavior of the monitored surface elements and therefore supports decisions on possible optimizations, e.g., improving the thermal comfort in a neighborhood. Appropriate visualization techniques facilitate decision-making and are thus crucial in the optimization process. In this study, we present a tool that eases the extraction of thermo-radiative features from multi-temporal thermographs taken from a monitored scene. Assisted by our tool, users can identify, choose, and register thermo-radiative features for each time step according to their individual research needs. The features’ temporal development is then visualized using a directed graph that encodes topological events as well as each feature’s size and summarizing statistics. To enhance this summary, a comprehensive animated sequence emphasizes the spatiotemporal behavior of the most significant thermo-radiative features. Salient developments are visually embedded and highlighted in the original infrared images, which are blended in an animation from time step to time step. Since we enable the user to interact with the data in a flexible way, noisy and low resolution image data sets can also be processed. 相似文献
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介绍了内陆湖泊水质遥感监测的特点及遥感监测水质的机理;总结了国内外近年来用于内陆湖泊水质参数反演的3种常用方法:经验模型、半经验法和机理模型法,并分析了3种模型的优缺点;讨论了目前遥感在水质监测应用中存在的问题和未来该领域研究的重点。 相似文献
13.
In earth and environmental sciences applications, uncertainty analysis regarding the outputs of models whose parameters are spatially varying (or spatially distributed) is often performed in a Monte Carlo framework. In this context, alternative realizations of the spatial distribution of model inputs, typically conditioned to reproduce attribute values at locations where measurements are obtained, are generated via geostatistical simulation using simple random (SR) sampling. The environmental model under consideration is then evaluated using each of these realizations as a plausible input, in order to construct a distribution of plausible model outputs for uncertainty analysis purposes. In hydrogeological investigations, for example, conditional simulations of saturated hydraulic conductivity are used as input to physically-based simulators of flow and transport to evaluate the associated uncertainty in the spatial distribution of solute concentration. Realistic uncertainty analysis via SR sampling, however, requires a large number of simulated attribute realizations for the model inputs in order to yield a representative distribution of model outputs; this often hinders the application of uncertainty analysis due to the computational expense of evaluating complex environmental models. Stratified sampling methods, including variants of Latin hypercube sampling, constitute more efficient sampling aternatives, often resulting in a more representative distribution of model outputs (e.g., solute concentration) with fewer model input realizations (e.g., hydraulic conductivity), thus reducing the computational cost of uncertainty analysis. The application of stratified and Latin hypercube sampling in a geostatistical simulation context, however, is not widespread, and, apart from a few exceptions, has been limited to the unconditional simulation case. This paper proposes methodological modifications for adopting existing methods for stratified sampling (including Latin hypercube sampling), employed to date in an unconditional geostatistical simulation context, for the purpose of efficient conditional simulation of Gaussian random fields. The proposed conditional simulation methods are compared to traditional geostatistical simulation, based on SR sampling, in the context of a hydrogeological flow and transport model via a synthetic case study. The results indicate that stratified sampling methods (including Latin hypercube sampling) are more efficient than SR, overall reproducing to a similar extent statistics of the conductivity (and subsequently concentration) fields, yet with smaller sampling variability. These findings suggest that the proposed efficient conditional sampling methods could contribute to the wider application of uncertainty analysis in spatially distributed environmental models using geostatistical simulation. 相似文献
14.
Geochemical reference materials (RMs) for microbeam techniques are typically characterised by averages and dispersion statistics (e.g., standard deviation, variance) that are calculated for a number of measurements (beam shots). It is proposed that the mapping of RMs will add spatial information that better characterises the grouping and magnitudes of the heterogeneities and provides the information necessary to define a minimum analytical mass. A simple mathematical solution is proposed, which can be easily computed and understood. The analogous notions to sill and range from geostatistics are applied to the minimum analytical mass versus the relative standard deviation. To assess grouping and magnitudes of the heterogeneities, a ‘proximity number’ is computed for each average value ± ‘n’ standard deviations (magnitude). Different chemical anomalies have been simulated to demonstrate the behaviour of the proximity number. To further test the proposed spatial geochemistry concept, sulfide‐ and oxide‐bearing RMs have been selected because many are crippled with nugget effect. They have been mapped with a micro‐XRF apparatus, and results are presented for CHR‐Bkg, CHR‐Pt+, MASS‐1, MASS‐3, WMS‐1 and WMS‐1a. MASS‐1 and MASS‐3 are the most suitable RMs for microbeam techniques. Spatial geochemistry offers a new approach to better characterise reference materials. 相似文献
15.
The study has been focused on examining the usage and the applicability of ensemble Kalman filtering techniques to the history
matching procedures. The ensemble Kalman filter (EnKF) is often applied nowadays to solving such a problem. Meanwhile, traditional
EnKF requires assumption of the distribution’s normality. Besides, it is based on the linear update of the analysis equations.
These facts may cause problems when filter is used in reservoir applications and result in sampling error. The situation becomes
more problematic if the a priori information on the reservoir structure is poor and initial guess about the, e.g., permeability
field is far from the actual one. The above circumstance explains a reason to perform some further research concerned with
analyzing specific modification of the EnKF-based approach, namely, the iterative EnKF (IEnKF) scheme, which allows restarting
the procedure with a new initial guess that is closer to the actual solution and, hence, requires less improvement by the
algorithm while providing better estimation of the parameters. The paper presents some examples for which the IEnKF algorithm
works better than traditional EnKF. The algorithms are compared while estimating the permeability field in relation to the
two-phase, two-dimensional fluid flow model. 相似文献
16.
R.J. Howarth 《Journal of Geochemical Exploration》1984,21(1-3)
This paper surveys recent developments in statistics as applied to exploration geochemistry in the spirit of Tukey's four major ingredients of Exploratory Data Analysis: graphical displays, transforms, robust (resistant) techniques, and residuals; and assesses their implications for future analysis of data from the prospecting environment. 相似文献
17.
A spatial and temporal analysis, at a city wide scale, is given of the main type of informal housing (favelas) in Rio de Janeiro.
Rapid change in the number and distribution of favelas and their inhabitants (favelados) over time is seen as the outcome
of two opposing sets of factors. Demand-led housing factors, including population growth and variations in levels of poverty
in the city, have constantly outstripped the supply side of the housing equation where inadequate housing policies and investment,
together with restricted building land have been characteristic. Added to these factors are a set of more specific developments
which shape the favela geography, including the timing and location of urban redevelopment, favela eradication and recognition,
transport development and access by the favelados to employment sources. Evidence shows that the contemporary distribution
of favelas in the city does not conform to spatial models of this urban form, and that any interpretation of the Rio favelas,
including their growth, development and diversity, needs to be space and time specific.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
David R. Hanson Thomas L. Vandergrift Matthew J. DeMarco Kanaan Hanna 《International Journal of Coal Geology》2002,50(1-4)
Today's highly productive coal mining systems represent large capital investments. Careful geotechnical planning and design are essential to protect these systems and to help ensure their overall success. Too often, however, the ability of the mine operator to adequately characterize the geotechnical environment and keep up with changing geologic conditions lags the advance rate of the mining equipment. Seismic tomographic imaging, based on the same principles as medical Computer-Aided-Tomography (CAT) Scans, offers the ability to identify changing geologic conditions, loading patterns, and the location of nearby abandoned mine workings. Although seismic tomography has been used for many years in the oil industry, until recently its practicality in the mining industry has been limited because the processes involved interfered with mining productivity and were labor-intensive in terms of data collection and interpretation. New advancements in signal processing have greatly enhanced the speed, resolution, and range of applications of tomographic imaging in underground coal mine settings.Many tomography applications in the mining industry use seismic velocity and/or attenuation tomography within a volume enclosed by the seismic source and receiver array. Although results obtained using this geometry work well in many situations, recent developments in reflection tomography show promise in eliminating the requirement that the target volume be surrounded by sources/receivers. For example, in-seam seismic reflection tomography may now be used to image structures and/or old workings from one general location in the mine (e.g., face areas of mains and panel developments) well ahead of planned developments—largely eliminating the need to probe-hole drill on regular intervals. These new developments have greatly expanded the ability of the mine operator to cost-effectively characterize previously inaccessible areas of the property.This paper gives an overview of the theories and processes involved in seismic tomography applicable to coal mine settings. Recent examples are presented of tomographic imaging applied to a variety of coal mine ground control problems and old works detection in the United States and Europe. The applicability of both seismic refraction and seismic reflection tomography is discussed. 相似文献
19.
《Geoforum》2015
This study explores the spatial transformation of urban South Africa since the ending of Apartheid rule two decades ago. It places this experience within the context of countries which have also gone through a “loosening” of political control and of related controls over spatial arrangements. The paper provides a discussion of South Africa’s spatial trends between 1996 and 2011, focusing on urbanisation; urban form; and socio-spatial segregation, and exploring the extent to which changes identified are shaped by the state, private sector investment, and the everyday actions of households and individuals. It shows that South Africa’s urban spatial transformation, post-Apartheid, is both idiosyncratic and comparable. The consequences of spatial controls, and of their loosening, have been diverse across countries, but also within countries. Loosening has led to differing relationships between state, citizenry and private enterprise, and to complex new crossing points between these groupings, affecting spatial change. In South Africa, significant trends have been: movement to the major cities where employment growth is stronger; levels of racial desegregation; and densification of parts of cities and towns, along with peripheral growth and employment decentralisation. Many of the changes however are differentiated across space and between settlements. While proactive state policies have had some impact (not necessarily in the direction of desired spatial transformation), and there are complex interrelationships, our empirical studies suggest that the major weight of evidence is towards the roles of private enterprise and people in shaping spatial change, enabled in part by forms of state loosening. 相似文献
20.
地学模拟技术的一个发展方向是与地学过程分析密切结合,另一个发展方向是与数据可视化技术相结合。前者试图通过使用各种数学方法模拟地学随机现象,并对这些不良结构化或半结构化的地学问题进行定量化描述;后者运用计算机的三维可视化功能,在三维环境下将空间信息管理、地学解译、空间分析、地学统计与预测、三维图形可视化等技术相结合,实现计算可视化、分析可视化、过程可视化、结果可视化和决策可视化,并用于地学分析。回顾了地学中计算机三维地学建模技术、地质统计学和地学非线性现象模拟方法,并对该领域的发展进行了展望,认为加强地学模拟的理论体系、方法体系、技术体系的研究和实践既有着重要的理论意义,又有着重要的现实意义。 相似文献