Geographic information is simply information that expresses and describes the location of objects and its features. It relates to the distribution and patterns of physical and human features that exist on the Earth's surface. Types of geographic information are as wide and varied as the field of Geography itself, from socio-economic or demographic data to physical and environmental data, it is usually treated as separate individual themes of similar types of information. Example, of geographic information are:
- Physical features or phenomena such as rivers, roads, forests, earthquakes, volcanoes, erosion, flood, vegetation etc.
- Human features or phenomena such as population, migration, electoral territories, poverty, health etc.
Geographical Information System (GIS) has evolved into a technology that is used by a large number of industries and agencies to help plan, design, engineer build and maintain information infrastructures that effects our everyday lives. The table below lists common users of GIS:
Industry Application of GIS
- Forestry Inventory and management of resources
- Police Crime mapping to target resources
- Epidemiology To link clusters of disease to sources
- Transport Monitoring routes
- Utilities Managing pipe networks
- Oil Monitoring ships and managing pipelines
- Government Evidence for funding anf policy implementation
- Health Planning services and health impact assessments
- Environment Agencies Identifying area of risk example- flood, earthquake etc.
- Healthcare Planning shortest routes
- Retail Store locators
- Marketing Location target customers
- Military Troop movement
- Telecommunication Business expansion
- Land-use Recording and managing land and property
- Real Estate Locating properties that match certain criteria
- Insurance Identifying risk
- Agriculture Analyzing crop yield
GIS software has a large variety of tools of varying level of complexity. Listed below are core standard functions that are common to most GIS application software packages:
- Mapping and cartography: Visualize and manipulate symbology and colors to create an output map with title, scale bar, north arrow etc.
- Query: Ask questions of feature attributes such as - Where is ...? What's the nearest....? What intersect with ....?
- Select: Identify features and their attributes that meet some criteria.
- Distance: Calculate the distance between the features.
- Buffers: Rings drawn around features at a specified distance from the features.
- Overlay: The display of multiple layer of information at one location.
- Clip: Cuts and input layer to the size and extent of a selected layer.
- Merge: Combines multiple layers into one layer
- Raster analysis: There is a whole separate set of tools for raster analysis that includes classifying cells, deriving aspect and slope, mosaicing and calculating new cell values among many others.
- 3D visualization: Data can be viewed with height in 3-dimensions for powerful visualization.
The greatest advantage of modern GIS technology is that all the functionality for working with multiple sets of geographic information are grouped and automated within one piece of software. In addition, it benefits from modern computer efficiency and speed.
Overall, the use of modern GIS offers many advantages over traditional paper maps:
- Can cop with large amount of data
- Can cover large study area (the whole world if required)
- Can conveniently select sub-study area
- Can cope with unlimited and frequent edits and changes
- More robust and resistant to damage
- Faster and more efficient
- Requires less resources (time, money and human resources)
