Geographic Information Systems (GIS)
Geographic Information Systems (GIS)
Geographic Information Systems (GIS) is a technology that can gather, store, analyze, manage, manipulate, map, and display information on a geographical location. GIS technology is a combination of computer-based tools, data, people, and methods that work together to perform tasks related to spatial data.
Although GIS is mostly associated with mapping, it is just one aspect of the functions of GIS. It can serve as a database and can also create geographic models by analyzing different sets of data in the GIS. The utility of GIS extends to facilitation of urban and resource planning and management. In addition, it has proven helpful in dealing with various real-world problems. This technology is being employed for various purposes such as land use planning, ecosystems modeling, landscape assessment and planning, transportation and infrastructure planning, market analysis, visual impact analysis, facilities management, tax assessment, and disaster management. A daily life example of GIS is the use of an Internet mapping program to locate directions. From protecting species to finding locations in real estate, GIS technology is employed across various disciplines.
Historical Background and Scientific Foundations
In order to obtain actionable insights using GIS, a user needs to create a specific question, feed in data from a database, decide the level of analysis, process the information, and obtain the visual representation. The main components of GIS are hardware, software, data, and people. GIS hardware includes a workstation, digitizer, data logger, and support equipment. Functions such as creating, editing, processing, and analyzing data are carried out by the software. The data used in GIS technology consists of a geodatabase and attribute data. A geo-database contains information on geographic locations, and the attribute data consists of support information. Lastly, GIS requires well-trained spatial analysts and GIS software specialists.
The origins of GIS can be traced back to 1959 when American geographer Waldo R. Tobler (1930–) created the MIMO (map in-map out) model. This model enabled the application of computer technology to cartography, thus replacing hand cartography. Concepts such as geocoding, data capture and analysis, and display were based on the MIMO principles.
GIS in its preliminary form, known as computer cartography, involved simple linework for depicting features on land, which later took the layered form to find out patterns and factors of spatial phenomenon. Further development happened in the mid-1960s when the Canada Geographic Information System (CGIS) was set up to take stock of the land inventory in Canada.
In 1964, the development of GIS gained further impetus with the establishment of the Urban and Regional Information Systems Association (URISA). This association encouraged the use of spatial technology to solve problems related to urban planning and environment. In the same year, geographer and mathematical cartographer Howard T. Fisher (1903–1979) founded the Harvard Laboratory for Computer Graphics and Spatial Analysis where path-breaking GIS applications were produced. It was in this lab that Fisher went on to develop SYMAP (Synagraphic Mapping System), a computer mapping software. The research carried out at the institute also led to the creation of other GIS applications such as CALFORM, SYMVU, GRID, Polyvrt, and ODYSSEY.
In 1967, the U.S. Bureau of the Census developed the Dual Independent Map Encoding (DIME) system. This development marked the first time GIS technology was used for large-scale digital mapping. Around the
WORDS TO KNOW
CARTOGRAPHY: The science of mapmaking.
GEOCODING: In geographic information systems, the assignment of geological data to particular features on maps or to other data records, such as photographs.
GEO-REFERENCING: The process used for referring information to a geographic region.
GEOSPATIAL INFORMATION: The combination of a huge range of information taken from various sources and referenced by a geographic region.
world, GIS technology continued to attain wider acceptance and application. In the same year, the U.S. Central Intelligence Agency (CIA) created the Automatic Mapping System (AUTOMAP), using its World Data Bank I, which had the representation of coastlines across the world.
In 1969, the Environmental Systems Research Institute (ESRI) was established, which produced ArcInfo and ArcView software. In September 1970, the
first GIS symposium was held in Ottawa, Canada. GIS technology proliferated in the 1970s. One of the first GIS projects to be implemented on a statewide level was initiated in 1973 in Maryland. The program was called the Maryland Automatic Geographic Information (MAGI). In the late 1970s, GIS technology evolved further with the development of ODYSSEY GIS, the first-ever vector GIS. ODYSSEY was developed at the Harvard Lab.
In the 1980s and 1990s, the GIS market saw the introduction of several applications. MapInfo, SPANS GIS, PAMAP GIS, INTERGRAPH, and SMALL-WORLD are some of the GIS applications produced during this period. GIS technology has rapidly evolved over the past 30 years. The revolution in the areas of information technology and communication technology together with the lowering cost of computer hardware has played an important role in the development and use of GIS.
In 1994, Ray R. Larson, a professor at the Berkeley School of Information Management and Systems, introduced the concept of Geographic Information Retrieval (GIR). GIR used the Web to provide access to GIS sources. Compared to traditional GIS, this method enabled more people to benefit from GIS databases and models. GIR managed to bring down the high cost bar-
riers and specialized talent, which impeded easy access to the technology.
Impacts and Issues
In the technology-driven twenty-first century, GIS is applied in every field where spatial information is required. Collecting weather data, enhancing weather forecasting technologies, mapping natural disasters like floods and earthquakes, and providing land and property-related information are some of the areas where GIS technology is applied extensively. Besides, it can be used to track human activities, which in turn can help in restoring the quality of our ecosystem. Apart from these, GIS has greatly benefited several areas of study such as environmental studies, geography, geology, planning, and business marketing among others.
However, several issues surround the use of GIS. Because this technology provides all sorts of data on a particular geographic location, there are privacy concerns. Its adoption has given rise to debates. The data stored in GIS are easily accessible to anyone in public libraries, which run on public funds and have to fulfill the growing demand for accessibility to GIS maps. The technology has the potential to be misused for terrorist or other criminal activities. Several municipal, provincial/state, and federal government agencies are employing a GIS privacy protocol to protect sensitive information such as military installations and nuclear facilities. Moreover, various government agencies are working toward restricting or destroying the availability of crucial information.
The costs associated with maintaining GIS are very high. As a result, this technology is mostly used by government bodies or agencies on a shared-cost basis. However, this has thrown open a debate regarding the ownership of the data. Moreover, because of shared access, agencies have to deal with the threat of data integrity. There is a risk of the information being manipulated or altered. The use of GIS has also given rise to international disagreements. Satellites have been deployed to aid GIS capture information from across the world. Economically backward nations have protested by claiming rights over the information thus collected.
The other issue concerns the adoption of GIS. This technology uses complex software, which forms a technical hurdle. Lack of librarians trained in GIS is another drawback. Additionally, the various processes involved in GIS such as gathering correct spatial data, determining the data format, entering data into the GIS, ensuring data quality, and incorporating a GIS into a decision-making process are difficult to implement. The high cost of hardware, software, as well as data and the maintenance costs involved in GIS pose yet another hurdle in the adoption of GIS technology.
Davis, B. E. Geographic Information Systems: A Visual Approach. OnWord Press, 1996.
DeMers, M. N. Fundamentals of Geographic Information Systems, 2nd ed. Hoboken: Wiley, 2000.
Heywood, I., S. Carver, and S. Cornelius. An Introduction to Geographical Information Systems. Boston: Longman, 1998.
AMBIOTEK. “Approaches to Developing a Web-based GIS Modelling Tool: For Application to Hydrological Nowcasting.” March 2003. http://www.ambiotek.com/theses/waleed_thesis_final.pdf (accessed February 26, 2008).
ESRI. “What Is GIS?” http://www.gis.com/whatisgis/ (accessed February 26, 2008).
GIS Development. “Mapping GIS Milestones” http://www.gisdevelopment.net/history/1960-1970.htm (accessed February 26, 2008).
Lynch, Margaret. The Geographer’s Craft Project, Department of Geography, University of Colorado at Boulder. “Ethical Issues in Electronic Information Systems.” 1994. http://www.colorado.edu/geography/gcraft/notes/ethics/ethics_f.html (accessed February 26, 2008).
U.S. Geological Survey. “Geographic Information Systems http://erg.usgs.gov/isb/pubs/gis_poster/#what (accessed February 26, 2008).
"Geographic Information Systems (GIS)." Environmental Science: In Context. . Encyclopedia.com. (September 19, 2018). http://www.encyclopedia.com/environment/energy-government-and-defense-magazines/geographic-information-systems-gis
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