A GIS, in the strictest sense, is a computer system for assembling, storing, manipulating, and displaying data with respect to their locations. However, modern GISs often assimilate data from multiple disparate sources in many different forms in order to answer queries and help analyze information. In a broad sense, a GIS not only converts and stores geographical information in digital form for analysis, but must also collects, transforms, aggregates, indexes, links, and mines related spatial databases. A modern GIS makes it possible to integrate information that is difficult to associate through any other means and combine mapped variables to build and analyze new variables.
With this broad perspective in mind, Shekhar and Chawla have done a marvelous job in presenting the fundamentals and trends in geographical information processing. The core of the book is a tour de force sequence of concepts and methods, progressively explaining models, languages and algorithms until we distinguish branches from trees and trees from forests. The authors not only explain the concepts but illustrate them well by numerous examples. They have emphasized the many nontrivial issues in integrating spatial data into traditional databases, ranging from deep ontological questions about the modeling of space to the important issues about file management. Each chapter is further supplemented by many thought-provoking exercises that aid readers in better understanding of the concepts and algorithms presented. The book ends by an excellent exposition of spatial data mining and future trends in spatial databases that helps readers appreciate emerging research issues.
This book is suitable as a textbook for an interdisciplinary course on geographical information systems, as well as a handy reference for people working in the area. Readers should find it easy to understand and apply the concepts and algorithms learned, even without any formal training in databases. Many disciplines will benefit from techniques learned in this book, leading to wider applications of the technology throughout government, business, and industry.
As one of the first books in this area, I am confident that you will benefit by what you learn in this exciting and rewarding area.
Prof. Benjamin Wah Univeristy of Illinois at Urbana-Champaign Department of Electrical and Computer Engineering 1101 W. Springfield Avenue Urbana, IL 61801 President, IEEE Computer Society (2001) March 2002