Geographic Information Systems

What Is a Geographic Information System? In 1988 the Federal Interagency Coordinating Committee defined the term Geographic Information System in the following manner: “a system of computer hardware, software, and procedures designed to support the capture, management, manipulation, analysis, and display of spatially referenced data for solving complex planning and management problems.” In essence, such […]
What Is a Geographic Information System? In 1988 the Federal Interagency Coordinating Committee defined the term Geographic Information System in the following manner: “a system of computer hardware, software, and procedures designed to support the capture, management, manipulation, analysis, and display of spatially referenced data for solving complex planning and management problems.” In essence, such a system is an electronic spreadsheet coupled with powerful graphic-manipulation and display capabilities. The three most important elements of a typical Geographic Information System can be summarized as follows: 1. Cartographic capability 2. Data management capability 3. Analytical capability The cartographic capabilities built into a Geographic Information System permit the computer – amply aided by skilled human operators – to produce accurate maps and engineering drawings in a convenient pictorial format. Once the digital maps have been constructed and annotated, the computer is used to manipulate the finished product in various specific ways to produce layered maps bristling with colorful attribute symbols. The data management capabilities enable the GIS operators to store and manipulate map-related information in convenient graphic and non-graphic formats. The storage and manipulation of the non-graphic information is often called “attribute processing”. Operators who are trained to handle the attribute processing can select the desired map data to produce colorful reports laced with a rich mixture of graphics, tabular information, and pictorial attributes. The analytical capabilities associated with today’s GIS software permit the trained operators to process and interpret spatial, tabular, and graphical data in a variety of useful ways. They can, for instance, measured the distance between two points or determine the areas of the various shapes pictured on the screen. The analytical capabilities also help the operators plan, design, and manage such important resources as roads, buildings, bridges, and waterways with maximum practical efficiency. Reaping The Practical Benefits of GIS Technology All around the world, government professionals, utility engineers, and efficiencyminded entrepreneurs have been quietly investing tens of millions of dollars in attempting to perfect a wide variety of Geographic Information Systems. The GIS routines they have been financing are capable of storing, manipulating, and analyzing complicated electronic maps to increase the efficiency of various largescale operations including city planning, resource management, emergency vehicle dispatch, and water distribution.
Even the simplest Geographic Information Systems contain a rich mixture of graphical and alphanumeric information stored in a database that can be manipulated electronically by trained human operators. The information contained in the various layers can be combined, modified, analyzed, and displayed in limitless combinations. The spatial information, its associated attributes, and any necessary alphanumeric labels and notations are imaged and printed using full-color computer-driven printers and video displays.
Regional and state governments, for example, use GIS to develop country maps, devise the most efficient deployments for public buses, repair roads, collect taxes, chart the spread of contagious diseases, and nail down new election districts. GIS technology is also being used in some of the most economically underdeveloped countries in the world. As you will learn at a later blog, technicians in Gambia, a tiny country on the West Coast of Africa, have been using GIS processing techniques coupled with inexpensive Navstar GPS receivers to monitor illegal fishing activities in their country’s territorial waters. Jack Dangermond, President of Environmental Systems Research; is convinced that Geographic Information Systems will rapidly spread to other Third-World countries whose citizens will experience immediate benefits. “GIS technology, because of its low-cost, high reliability, user-friendliness and wide usefulness, will be adopted by many users outside the highly developed technological societies,” he asserts. “This offers tremendous promise for improving the future for billions of people on planet Earth.” Of course, Geographic Information Systems will be broadly adopted by users around the world only if sponsors can foresee measurable economic benefits. Fortunately, for several decades, such benefits have been reported in industry literature and by many users. In 1968, for instance, the Texas Electronic Service Company introduced a grid-based load-management system for its massive electrical transformers. Using rather primitive GIS techniques, company technicians easily found and documented $1 billion in savings over a four-year period. Similarly, when the Denver Water Department implemented a GIS-based system for its engineering and planning functions, professional technicians on their staff pinpointed immediate savings in time, energy, and labor. Before automation, drafters typically spent two months turning out drawings for each set of 100 cross-sectional maps. After automation, those same products were typically completed in less than two days