Showing papers on "Spatial analysis published in 1982"

Methods for Analysing Spatial Processes of Several Types of Points

Abstract: Two approaches are described to the analysis of spatial patterns consisting of several types of points. The first approach uses a method of asymptotically unbiased estimation of the second moment distribution; the second uses methods based on regions of empty space in the patterns. Some distributional results are given in each case, and a method of Monte Carlo testing conditional on the marginal structure is described. The methods are illustrated by being applied to some physiological data.

Heuristic approaches to spatial analysis in archaeology

Abstract: This article discusses an approach to spatial analysis which is more closely tailored to archaeological objectives and archaeological data than are more "traditional" quantitative techniques such as nearest neighbor analysis. Heuristic methods, methods which make use of the problem context and which are guided in part by intuitively derived "rules," are discussed in general and with reference to the problem of spatial analysis in archaeology. A preliminary implementation of such a method is described and applied to artificial settlement data and artifact distributions from the Magdalenian camp of Pincevent. Finally, the prospects for further development of heuristic methods are elaborated. SPATIAL ANALYSIS MAY BE SEEN as a process of searching for theoretically meaningful patterns in spatial data. Of course, this problem has been approached by archaeologists in several ways. The most obvious method of spatial analysis is the visual examination of a point distribution on a map with relevant background information in mind. This intuitive approach has been forsaken (and berated) by many archaeologists with greater aspirations to rigor, in favor of quantitative techniques of spatial analysis, such as nearest neighbor analysis. These techniques generally yield a summary statistic which attempts to characterize the spatial pattern with a single number and perhaps test its significance. The summary statistic is commonly compared from period to period or from area to area. This article reports the progress of an experiment in an alternative approach to the analysis of spatial patterns. This approach, the heuristic approach, is synthetic in that it attempts to open the way for the use of contextual knowledge and human expertise within a formal (computerexecuted) procedure for aiding human-directed spatial analysis. This presentation starts with a brief review of "traditional" quantitative approaches to spatial analysis. It is followed by a discussion of heuristic approaches to problem solving and their application to spatial analysis in archaeology. In the next section, heuristic procedures that have been developed are applied to artificial data sets and then to an analysis of actual data from the Magdalenian camp of Pincevent. The article closes with a discussion of the conclusions of this experiment and prospects for further development.

Modelling the Spatial Distribution of Suburban Crime

Abstract: This paper examines the spatial distribution of crime among Chicago's suburbs by completing a spatial autocorrelation and regression analysis of crime occurrence rates. The results suggest that there is little interjurisdictional spillover of violent crime among the suburbs of Chicago. Rather, the clustered spatial pattern of crime and its decay with distance to the city of Chicago reflects the nonrandom spatial distribution of offender rates. The distribution of property crime exhibits neither spatial autocorrelation nor a relationship with distance to Chicago. Instead, it is closely associated with the location of retail and manufacturing activities. This suggests that the journey to property crime extends many miles and crosses suburban boundaries.

Spatial aggregation in gravity models: 2. One-dimensional population density models.

Abstract: This paper, the second of four, is concerned with applying a methodology for analysing the spatial aggregation problem in gravity models outlined in the first paper. The methodology is based on a consistent framework for linking measures of pattern in interaction data to the derivation and estimation of related interaction models using spatial information theory. In this quest, a link is forged between information in data and the parameters of an associated model, and in part 1 it was suggested that if this link could be formalised then a means would be available for predicting changes in model parameters from different aggregations of the data, prior to the actual estimation of the models themselves. This relationship can be formalised for the case of the continuous one-dimensional interaction model such as the population density model, and this paper is concerned with demonstrating such an application to aggregations of zones in the Reading region. The framework is first described and two continuous mod...

Spatial Autocorrelation Analysis of Biological Variation on Bougainville Island

Abstract: The large and rich data set collected on Bougainville Island during 1966–67 and 1970 has already been subjected to numerous analyses in vogue during the past decade (Friedlaender, 1971a,b, 1975; Friedlaender et al., 1971). These and related analytical techniques are employed in other articles in this volume to perfectly suitable ends. It seems most appropriate here to introduce, to the anthropological audience, a different analytical technique from the fieds of population biology and geography to see what new light it might cast upon this particular body of data and to examine the advantages and disadvantages of this approach as contrasted to those now in common usage.

Geometry and Spatial Interaction

Abstract: This paper explores the relations between regional shape geometry and internal regional geometry affiliated with spatial interaction. Because properties of these two geometries are difficult to measure, various indices are calculated. Using the canonical correlation technique, the study then analyzes the relationship between these two geometries. This yields two interesting findings: (1) that a relationship does exist between the two types of geometry, and (2) that a connectivity matrix depicting geographic configuration can, in part, measure the regional shape involved. The research employs data for the journey to work in 24 selected Canadian urban areas.

The spatial organization of cancer mortality

Abstract: The examination of human cancer occurrence from a spatial perspective can yield useful information that aids in the search for factors that influence cancer risk. The spatial implications of theoretical models of carcinogenesis suggest an approach for empirically testing theories relating to this problem. The spatial analysis of empirical cancer data can yield clues leading to the development and testing of causal hypotheses. Different models of the relationship between cancer risk and environmental factors yield different expected spatial patterns for two forms of skin cancer, malignant melanoma and other skin cancers. The empirical patterns are in basic agreement with those expected. Both lung and skin cancers exhibit complex patterns of spatial variation among U.S. counties. One-dimensional spatial analysis is used in this study to decompose these patterns by spatial scale in order to assess the nature of possible environmental risk-affecting agents. Large-area variation (or regional trend) is...

A hybrid structure for the storage and manipulation of very large spatial data sets

Abstract: The map data input and output problem for geographic information systems is rapidly diminishing with the increasing availability of mass digitizing, direct spatial data capture, and graphics hardware based on raster technology. Although a large number of efficient raster-based algorithms exist for performing a wide variety of common tasks on these data, there are a number of procedures which are more efficiently performed in vector mode or for which raster mode equivalents of current vector-based techniques have not yet been developed. A hybrid spatial data structure is presented, named the vaster structure, which can utilize the advantages of both raster and vector structures while potentially eliminating, or greatly reducing, the need for raster-to-vector and vector-to-raster conversion. Other advantages of the vaster structure are also discussed.

A graph-relational approach to geographic databases

Abstract: This paper treats the modeling of an important class of databases, i.e., geographic databases, with emphasis on both structural (data definition) and behavioral (data manipulation) aspects. Geometric objects such as polygons, line segments, and points may have different relations among each other (such as order, adjacency, connectivity) and can be represented in a uniform spatial data structure (structure graph). The dynamic behavior is defined by a finite set of consistency-preserving state transitions (productions) where coincidence problems as well as topological properties have to be solved. Moreover, the graph grammar approach can be used to study the synchronization of several concurrent productions (Church-Rosser properties).

A Comparative Study of Some Stochastic Methods and Autoprojective Models for Spatial Processes

Abstract: Spatial stochastic processes often show a distinct persistence, which becomes noticeable in a nonrandom spatial grouping of similar or regularly dissimilar values. Various methods have been developed for statistically analyzing such persistence effects which are dependent upon distance and direction. Important differences and similarities in the concept of spatial autocorrelation and the theory of regionalized variables will be pointed out and explained by means of examples. The use of these geostatistical methods in modelling spatial processes leads to the SAR (spatial auto-regressive) models and to the Kriging concept, respectively. Although SAR models are used in particular to represent spatial persistences as characteristic endogenous dependency structures, the Kriging method is more pragmatically orientated to the interpolation and extrapolation of spatial data. The suitability of such stochastic models in purely spatial forecasting and also in the estimation of areal means will be described by use o...

Regression methods for spatial data

Abstract: The kriging approach, a parametric regression method used by hydrologists and mining engineers, among others also provides an error estimate the integral of the regression function. The kriging method is explored and some of its statistical characteristics are described. The Watson method and theory are extended so that the kriging features are displayed. Theoretical and computational comparisons of the kriging and Watson approaches are offered.

Randomness and order in the topology of settlement systems.

Abstract: The frequency distribution of settlement links forms the basis of a linear programming methodology which can be utilized to analyze the structure of settlement systems. The resulting index of system topology is compared to a more conventional measure Gearys contiguity coefficient which may be applied when the problem is conceptualized as one of spatial autocorrelation on a k-color map. The index of linkage similarity that is introduced appears to have a useful advantage over the Geary measure. The Geary and linkage similarity indices are used to examine the topology of four Canadian and two hypothetical settlement systems. (EXCERPT)

Potential of multisensor data and strategies for data acquisition and analysis

Abstract: Registration and simultaneous analysis of multisensor images is useful because the multiple data sets can be compressed through image processing techniques to facilitate interpretation. This also allows integration of other spatial data sets. Techniques being developed to analyze multisensor images involve comparison of image data with a library of attributes based on physical properties measured by each sensor. This results in the ability to characterize geologic units based on their similarity to the library attributes, as well as discriminate among them. Several studies can provide information on ways to optimize multisensor remote sensing. Continued analyses of the Death Valley and San Rafael Swell data sets can provide insight into tradeoffs in spectral and spatial resolutions of the various sensors used to obtain the coregistered data sets. These include imagery from LANDSAT, SEASAT, HCMM, SIR-A, 11-channel VIS-NIR, thermal inertia images, and aircraft L- and X-band radar.