Geographical information system Essay
Geographical information system
A Geographic Information System (GIS) is a system for generating, storing, analyzing and managing spatial data and associated attributes. More precisely, GIS is a computer system capable of integrating, storing, editing, analyzing, sharing, and displaying geographically-referenced information. In a more generic sense, meanwhile, GIS is a device that allows users to generate interactive queries, analyze the spatial information and edit data.
Heywood, Cornelius, and Carver (2006) explain that GIS technology can be used for scientific investigations, resource management, asset management, Environmental Impact Assessment, development planning, cartography, and route planning. Like the computer, this technology is another of man’s inventions that aims to make things a lot easier for the humankind.
Berry (1993) said that “many industries can actually gain considerable benefits from GIS technology” (p. 424). An active GIS market has brought about lower costs and continual improvements in the hardware and software components of GIS. These developments will, in turn, result in a much wider use of the technology throughout science, government, business, and industry, with applications including real estate, public health, crime mapping, national defense, sustainable development, natural resources, transportation and logistics. GIS is also diverging into Location Based Services (LBS).
LBS allows GPS allowed mobile devices to show their location in relation to fixed assets such as nearest restaurant, gas station, fire hydrant and in terms of mobile assets such as friends, children, police car or to relay their position back to a central server for display or other processing. These services continue to develop with the increased integration of GPS functionality with more and more powerful mobile electronics.
Benefits of GIS
Wise (2002) noted that “maps have conventionally been used to explore the Earth and to utilize its resources. GIS technology, as an offshoot of cartographic science, has improved the efficiency and analytic power of traditional mapping” (p. 352). Now, as the scientific community recognizes the environmental consequences of human activity, GIS technology is becoming an important tool in the effort to appreciate the process of global change. Various map and satellite information sources can come together in modes that reproduce the interactions of complex natural systems.
Through a function known as visualization, a GIS can actually be utilized to produce various images. And we’re not only talking about maps but drawings, animations and other cartographic products. These images enable researchers are systematically helpful in transmitting the technical concepts of GIS study-subjects to non-scientists. As ordinary mortals, we can easily grasp the meanings behind these images.
In line with this, Burrough and McDonnell (1998) reported that geographic information systems have emerged in the last decade as an essential tool for urban and resource planning and management. Their capacity to store, retrieve, analyze, model and map large areas with huge volumes of spatial data has led to an extraordinary proliferation of applications. Geographic information systems are now used for land use planning, utilities management, ecosystems modeling, landscape assessment and planning, transportation and infrastructure planning, market analysis, visual impact analysis, facilities management, tax assessment, real estate analysis and many other applications (p. 327).
A GIS is a collection of hardware, software, data, organizations, and people who use GIS as a tool to characterize and analyze geographic data. A GIS references real-world spatial data elements to a coordinate system. These features can be alienated into different layers. Since its main existence is to simplify things, a GIS can also store attribute data, which is descriptive information of the map features. This information is placed in a database separate from the graphics data, but is linked to them. GIS allows the inspection of both spatial and attribute data at the same time, and lets users search the attribute data and relate it to the spatial data.
Furthermore, Bolstad (2005) illustrates two of the most popular types of spatial data. Raster references spatial data using a grid of cells or pixels (p. 544). The other type is the vector data references spatial data which uses a series of coordinates. Raster data includes different numerical values for each pixel making raster data more suitable for representing features without discrete boundaries such as forest cover type and precipitation. Vector data, on the other hand, consists of points, lines or arcs, or polygons or areas). These features are recorded by a series of coordinates. Vector data are more suitable for features that have distinct boundaries such as roads and houses.
According to Thurston, Poiker, and Moore (2003) acquiring data to place into a GIS is a large subject in itself that contains a number of different approaches. One of the most common ways to collect spatial geographic data is to perform a physical survey. This includes surveying the land, underwater areas, and underground features of the earth (p. 134).
Aerial photography is an ever more popular way to gather spatial data. Aerial photographs are taken from an aircraft, after which they are measured and interpreted. Similarly, satellite remote sensing can be interpreted for physical features and attributes.
Meanwhile, Wheatley and Gillings (2002) listed the three main components of GIS namely: hardware, software and human resources. GIS hardware are computers, input devices, printers, storage systems and computer configuration/networks. Computers for GIS usage can be PCs at the low end, or supercomputers and X-Terminals at the high-end, these computers can be stand-alone units or connected into a network environment. Input devices are digitizers and scanners. These devices are used to produce a hardcopy map. There are numerous types of printers including: matrix, inkjet/bubblejet and laser. Finally, GIS storage systems include: optical disks, magnetic disks, floppy disks or magnetic tapes (p. 252).
According to Bolstad (2005), “GIS data represents real world objects like roads, land use, elevation with digital data. Real world objects can be divided into discrete objects and continuous fields. There are two broad methods used to store data in a GIS for both abstractions: Raster and Vector.” (p. 543).
At present, digitizing is the most common technique for translating existing maps and images into digital form. This process may seem to be boring, especially high-density maps. Scanners, on the other hand, can replace digitizing by automatically converting hard-copy maps to a digital raster file.
The third hardware component is the printer/plotter. GIS related software includes both the GIS program itself and special application packages, such as digital environment modeling and network analysis. The main difference between GIS software programs and desktop mapping programs is the ability of GIS programs to perform spatial analysis.
For Heywood, Cornelius, and Carver (2006), “desktop mapping programs suggest many of the same features as a GIS, but their ability to support spatial analyses are limited” (p. 248). They are developed to satisfy individual user needs for mapping presentations. Public domain GIS software packages are GIS programs developed by government and universities, available free or for a nominal cost. Human resources used to operate a GIS typically include: operational staff that normally monitor the design of map displays; technical professional staff, and management personnel.
Technical professional staff are information analysts who answer particular user problems and satisfies their information needs, system administrators, who are responsible for maintaining the system (hardware/software) in a continuous operational mode, programmers, who translate the application specifications prepared by the analyst into programs and the database administrator, who assists the analysts, programmers and users to organize geographic features into layers, identify sources of data, develop coding structures for non-graphics data, and document information about the contents of the databases.
Heywood, Cornelius, and Carver (2006) further said that management personnel include the manager who monitors the daily performance of the GIS project implementation team and manages the output production as required by the organization and the Quality Assurance coordinator who provides quality assurance to the team, and manages the output of the final product to ensure it meets the conversion specification and data acceptance plan (p. 250).
GIS technology is such an important tool in today’s growing technology-hungry populace. The system not only simplifies matter for every specialist but for every human being as a whole. With the technology, we become easily aware of certain things that were normally difficult to grasp.
The system is certainly a good way to improve information management, obtain higher quality analysis and improve project efficiency. No one from our ancestors may have thought that things would become a lot easier through this technology.
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Bolstad, P. GIS Fundamentals: A first text on Geographic Information Systems, Second Edition. White Bear Lake, MN: Eider Press. 2005. Pp. 543
Burrough, P.A. and McDonnell, R.A. Principles of geographical information systems. Oxford University Press, Oxford. 1998. Pp. 327
Chang, K.S. Introduction to Geographic Information System, 3rd Edition. McGraw Hill. 2005
Heywood, I., Cornelius, S., and Carver, S. An Introduction to Geographical Information Systems. Prentice Hall. 3rd edition. 2006
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