Geographic Information System (GIS)


• Survey measurement, pipe, valve, meter, address, street intersection, zip code, etc

– Information

• Flat file, relational database table, spreadsheet, scanned image, digital photo, CAD file, etc

– System

• Records Management, Watershed, Flow Modeling, Customer Billing, Valve Maintenance, Valve Isolation Trace, Customer Information system….

GIS a formal definition : A system for capturing, storing, checking, integrating, manipulating,analyzing and displaying data which are spatially referenced to the Earth. This is normally considered to involve a spatially referenced computer database and appropriate applications software”

Capturing Data

A GIS must be able to handle two fundamental data types: Geographic data. This type of data is coordinate based and represents the physical distribution of elements in the GIS . Tabular data. This type of data contains the attributes, or characteristics, about elements in the GIS.

Storing Data

Geographic GIS data is stored primarily in one of 2 types: Raster, which is image based. A raster data model assigns values to cells on a computer screen which covers a specific location. Vector, which is coordinate based model used to represent real-world features.

Querying Data

A GIS must provide tools by which its users can answer questions. A query can be based upon the use of the GIS to identify a specific feature OR its use to identify features based on a specific set of conditions.

Analyzing Data

A GIS must be capable of answering questions regarding the interaction of spatial relationships

Displaying the Data

A GIS must allow a flexible environment for its users to view the data. Data may be displayed in multiple formats, but generally is viewed as either a graph, table, or map


A GIS must have the means to output the data in usable formats .Common forms of output include: Images, Documents, Paper maps, The internet ,Files for use in other applications

Different data sources and data types are linked using the location at which the data is collected or its association to a place or address. A GIS can link to and access information that is shared from the field or read from a departmental database anywhere on the network. In addition, time-critical information collected by real-time sensors and broadcast from notification systems can be combined to improve situational awareness.

  • spatial location – usually a geographic location
  • information – visualization of analysis of data
  • system – linking software, hardware, data
  • personnel – a thinking explorer who is key to the power of

The 3 “W’s” of Geography

  • What is where
  • Why is it there
  • Why do I care

Spatial and Attribute Data

  • Spatial data (where)
  • specifies location
  • stored in a shape file, geodatabase or similar geographic file
  • Attribute (descriptive) data (what, how much, when)
  • specifies characteristics at that location, natural or human-created
  • stored in a data base table

GIS systems traditionally maintain spatial and attribute data separately, then “join” them for display or analysis

  • for example, in ArcView, the Attributes of … table is used to link a shapefile (spatial structure) with a data base table containing attribute information in order to display the attribute data spatially on a map

GIS can helps businesses develop

GIS has been recognized as a powerful tool for developing effective due to the geographic nature of the data and models. GIS helps businesses develop an effective plan by addressing the following:

• Damage assessment and repair during emergencies

• Employee (and family) notification

• Evacuation

• Facilities management

• Mitigation strategy development

• Office relocation

• Supply chain assessment

• Threat assessment

• Vulnerability analysis

• Weather mapping

Quickly browse and find maps and apps.

Why Study GIS?

  • 80% of local government activities estimated to be geographically based
    • plats, zoning, public works (streets, water supply, sewers), garbage collection, land ownership and valuation, public safety (fire and police)
  • a significant portion of state government has a geographical component
    • natural resource management
    • highways and transportation
  • businesses use GIS for a very wide array of applications
    • retail site selection & customer analysis
    • logistics: vehicle tracking & routing
    • natural resource exploration (petroleum, etc.)
    • precision agriculture
    • civil engineering and construction

GIS can help a business prepare for disruptions to minimize potential effects

  • Military and defense
    • Battlefield management
    • Satellite imagery interpretation
  • scientific research employs GIS
    • geography, geology, botany
    • anthropology, sociology, economics, political science
    • Epidemiology, criminology

Some Ways GIS is Used

  • Emergency Services – Fire & Police
  • Environmental – Monitoring & Modeling
  • Business – Site Location, Delivery Systems
  • Industry – Transportation, Communication, Mining, Pipelines, Healthcare
  • Government – Local, State, Federal, Military
  • Education – Research, Teaching Tool, Administration

Upcoming International ECPD Institute events and activities: