Editorial

Abstract

Encyclopedia of Human Geography, Gerald R. Pitzl, Westport, Connecticut: Greenwood Publishing. 2004.320 pages. ISBN 0-313-32010-1 $59.95 (paper)a

River Channel Management: Towards Sustainable Catchment HydrosystemsPeter W. Downs and Kenneth J. Gregory New York: Oxford University Press. 2004. 395 pages. ISBN: 0-340-75969-0. $35.00 (paper)

Maps of the Imagination: The Writer as CartographerPeter Turchi San Antonio, Texas: Trinity University Press, 2004. 246 pages. ISBN: 1-59534-005-X. $24.95 (hardcover)     

Editorial

Abstract

With the increase in volume of spatial data now available, more effective ways must be found of storing and processing these data. This paper presents a compacted version of the linear quadtree and a spatially-referenced index method that can significantly reduce the storage requirements of a set of images and the time taken to process spatial queries. The index acts as a high-level summary of a regular-sized portion of the underlying image and so can be used to avoid examining areas of the image where none of the required features is present. Some example results are given. A method for the optimization of spatial searches is presented which takes into account the area and distribution of features within an image. Finally, a method for directly associating the edges of features with the individual nodes of a quadtree is reported. This is important since the edges of objects are no longer explicitly present in linear quadtrees and so must be recalculated when they are required for part of a query. Recalculation of object edges or boundaries is expensive; it is best, therefore, to perform the operation once only, and then save the results.     

Editorial

This paper addresses the problems associated with the integration of data between incongruent boundary systems. Currently, the majority of spatial boundaries are designed in an uncoordinated manner with individual organizations generating individual boundaries to meet individual needs. As a result, current technologies for analysing geospatial information, such as geographical information systems (GISs), are not reaching their full potential. In response to the problem of uncoordinated boundaries, the authors present an algorithm for the hierarchical structuring of administrative boundaries. This algorithm applies hierarchical spatial reasoning (HSR) theory to the automated structuring of polygons. In turn, these structured boundary systems facilitate accurate data integration and analysis whilst meeting the spatial requirements of selected agencies. The algorithm is presented in two parts. The first part outlines previous research undertaken by the authors into the delineation of administrative boundaries in metropolitan regions. The second part outlines the distinctly different constraints required for administrative-boundary design in rural areas. The development of the algorithm has taken place in a GIS environment utilizing Avenue, an object-orientated programming language that operates under ArcView, the desktop software developed and distributed by ESRI.