A Comprehensive Framework for Exploratory Spatial Data Analysis: Moran Location and Variance Scatterplots

International Journal of Digital Earth, Volume 3, Issue 2 June 2010 , pages 157 – 186

J. G. Negreiros; M. T. Painho; F. J. Aguilar; and M. A. Aguilar

“A significant Geographic Information Science (GIS) issue is closely related to spatial autocorrelation, a burning question in the phase of information extraction from the statistical analysis of georeferenced data. At present, spatial autocorrelation presents two types of measures: continuous and discrete. Is it possible to use Moran’s I and the Moran scatterplot with continuous data? Is it possible to use the same methodology with discrete data? A particular and cumbersome problem is the choice of the spatial-neighborhood matrix (W) for points data. This paper addresses these issues by introducing the concept of covariogram contiguity, where each weight is based on the variogram model for that particular dataset: (1) the variogram, whose range equals the distance with the highest Moran I value, defines the weights for points separated by less than the estimated range and (2) weights equal zero for points widely separated from the variogram range considered. After the W matrix is computed, the Moran location scatterplot is created in an iterative process. In accordance with various lag distances, Moran’s I is presented as a good search factor for the optimal neighborhood area. Uncertainty/transition regions are also emphasized. At the same time, a new Exploratory Spatial Data Analysis (ESDA) tool is developed, the Moran variance scatterplot, since the conventional Moran scatterplot is not sensitive to neighbor variance. This computer-mapping framework allows the study of spatial patterns, outliers, changeover areas, and trends in an ESDA process. All these tools were implemented in a free web e-Learning program for quantitative geographers called SAKWeb© (or, in the near future, myGeooffice.org).”

Esri Map Book Encapsulates 25 Years of GIS Development

Twenty-Fifth Anniversary Volume Includes Comparative Historic Maps

Esri has published volume 25 of its popular Map Book series. This commemorative edition includes a “then and now” section that compares similar maps from the 25-year period, making it of particular interest to cartographers, geographic information system (GIS) professionals, and geography students.

“This year’s map book marks a milestone,” says Jack Dangermond, Esri president. “For a quarter of a century, this publication has chronicled the rapid evolution of GIS and celebrated the achievements of GIS users in a wide range of industries. This volume republishes a selection of maps printed in early editions of Esri Map Book. It is shown with similar maps made with current ArcGIS software and illustrates how far we’ve come.”

Including more than 100 full-color maps, the annual Esri Map Book showcases the most creative and compelling and best-designed maps presented at the annual Esri International User Conference Map Gallery exhibition. Each map includes a description indicating how it was produced and used.

Esri Map Book, Volume 25 (ISBN-13: 978-1-58948-254-8, 120 pages, $24.95), is available at online retailers worldwide, at www.esri.com/esripress, or by calling 1-800-447-9778. Outside the United States, visit www.esri.com/esripressorders for complete ordering options, or visit www.esri.com/distributors to contact your local Esri distributor. Interested retailers can contact Esri Press book distributor Ingram Publisher Services.

[Source: Esri press release]