Geographical information system (GIS) is a computer based information system that enables capture, management, manipulation and analysis, retrieval and presentation of geographically referenced data. Geographically referenced data refers to data that has specific location according to geographic referencing system address (UTM coordinate system). GIS has the ability to store, retrieve, manipulate and analyse a range of spatially related data. With a GIS the user may ask questions of data related to the map, search for patterns and distributions and investigate the underlying relationships between different sets of data. It is a special class of information systems that keep track not only of events, activities, and things, but also of where these events, activities, and things happen or exist.
Geography can be considered the mother of all other disciplines as everything happens at a location on the earth
surface. Everything is mappable and hence GIS can be applied in every field of life.It can be likened to cancer which affects virtually every part of the human body. In the same way GIS can be applied everywhere, in every field, due to the aspect of location which is a common denominator. Geography is concerned with answering the what? where? how? and why? questions that describe any space on the earth’s surface. The what? question refers to the name of the geographic phenomena, while where? refers to the location. How? refers to the distribution and the why? Question attempts to explain the reason for the distribution by demonstrating the relationship between various geographic phenomena.
Geographic Information Systems all started in 1854. Cholera hit the city of London, England. British physician John Snow began mapping outbreak locations, roads, property boundaries and water lines. Once he added these features to a map, he discovered that Cholera cases were commonly found along the water line.It was a major event connecting geography and public health safety. This marked the beginning of spatial analysis and the start of a whole field of study: Epidemiology – the study of the spread of disease.It wasn’t until 1968 that GIS evolved to using computers. Roger Tomlinson first used the term “Geographic Information System” in his paper “A Geographic Information System for Regional Planning”. GIS became computer-based tools for storing and manipulating map-based land data.
Currently, GIS has 6 components: hardware, software, network, procedures, georeferenced data and the user community.In the last decade this technology has continued to evolve with other computer related technologies and programs. For instance the user community has grown from geographers, surveyors and cartographers to other professions in other fields. The knowledge of where things are happening is now a requirement in management of resources.In addition, the hardware and software have improved in terms of data speed,storage and cost. New versions of GIS packages with easy to use tools are now available in the market at competitive cost. In fact open –source packages are now available for free online and they come with a variety of tools for different applications.
GIS is much more than a container of maps in digital formrevealing patterns and processes in geographic information. It is a computerized tool for solving geographic problems and a spatial decision support system. Applications of GIS are in all sectors in the world and it simplifies life in so many ways. For instance, GIS may be used in management of forestlands and wildlife, determining shortest route in disaster evacuation efforts; mapping water resources; mapping health facilities and disease spread; management of tourism; population mapping; marketing and distribution; urban planning; utility management and provision of essential services among so many other applications. GIS is therefore, a must-have skill today in every sector as the world is now focusing on sustainable development goals (SDGs) where sustainable management of both human and natural resources is crucial.
By Mercy K