Geographical Information Systems

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Geographical Information Systems

• Andrew Pearce

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Definition

• A Geographical Information System is a
  collection of spatially referenced data (I.e.
  data that has locations attached to it) and the
  tools required to work with the data

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Geographical Information Systems

• We are constantly making decisions based on
  spatial data you will, for example know the
  quickest way to get to school from your home.
• Occasionally though we are asked a question that
  depends on the spatial data that we hold. For
  example a motorist may stop and ask us the best
  route to the motorway.
• The spatial databases we have in our brains are
  developed over a period of time and needs to be
  regularly updated as the environment around us
  changes.

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Geographical Information Systems

• If you move to a new area this Human Store of
  spatial data needs to be developed from scratch
  with new details about the locations of landmarks
  such as
• Shops
• Banks
• Bus Stops
• Railway Stations
• Schools
• Hospitals

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Geographical Information Systems

• A GIS creates maps from data pulled from
  databases.
• Existing maps can be Digitized and translated
  into GIS.
• as well.
• Making GIS maps is much more flexible and than
  traditional manual or automated cartography.
• approaches.
• A GIS based cartographic database can be both.
• continuous and scale free.
• A map can be created anytime to any scale for
  anyone,
• as long as you have the data.

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The Spatial Element

• When databases have the Spatial Element added
  they.
• become very useful indeed. For example
• An ordinary telephone directory is arranged
  according to each surname, with the address and
  telephone number alongside. So if you want a list
  of telephone numbers for everyone in your street,
  the only way to do this is to look through the
  whole telephone directory noting phone numbers
  corresponding with addresses on your street -
  This would take a very long time.
• A GIS would make this task very simple quick.

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What Makes A GIS?

• A GIS is a Collection of
• Hardware.
• Software.
• Geographic Data.
• Personnel.
• Training.
• All designed to Efficiently CAPTURE, STORE,
  UPDATE, MANIPULATE, ANALYSE DISPLAY all manner
  of geographically referenced information.

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Software

• Provides functions tools needed to
• Store, Analyse Display information about
  places.
• The key components are
• Tools for entering manipulating geographic
  information such as addresses or political
  boundaries.
• A Database Management System.
• An easy to use GUI.
• Tools to create intelligent digital maps that can
  be analysed, query for more info, or print for
  presentation.

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Components

• A GIS is a combination of
• Essential elements of a relational database.
• .
• Computer Cartography (Computerised Maps).
• One important characteristic of GIS is that every
  feature on the map is linked to a record in the
  database and may be related to other databases as
  well.
• They can be thought of as INTELLIGENT MAPS.

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Data

• A GIS can use data from a wide range of formats
  standard.
• map and graphics file formats, images, CAD files,
• spreadsheets, relational databases, and many more
  sources.
• Data is free or fee-based and comes from
• Commercial.
• Non-Profit organisations.
• Educational institutes.
• Government sources.
• Other GIS software users.
• Your own organisation.

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Personnel

• Thousands of organisations in hundreds of
  industries are looking for.
• individuals with formal training and practical
  experience with GIS.
• GIS careers typically include positions such as
• Project Manager.
• Computer Programmer.
• Database Administrator.
• System Administrator.
• Cartographic Designer.
• Business Development.
• GIS has become such an important part of many
  organisations.'
• information management strategy that it has
  resulted in the creation of
• a new position
• Geographic Information Officer.

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Training

• Whether your use of GIS is casual or
  professional, some form.
• of education or technical training is highly
  recommended.
• GIS applies a scientific process to the tasks
  for.
• which it is used. Good training will better equip
  you.
• to understand that process and apply it properly.
• There are 4 main methods of learning GIS
• Instructor-Led Technical Training.
• Online Learning.
• Self Study.
• Formal GIS Degree or Certification Programs.

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Data Capture For GIS

• Capturing data for GIS is Time Consuming
  Painstaking.
• The main methods used are
• Hand tracing a map with a mouse or Puck to
  collect coordinates of features.
• Using an electronic scanning device to convert
  map lines and points to digits.
• Keying in the data
• For example Colne Valley Water Company, keyed
  in
• details of 2,700 Km of pipes together with
  attribute data,
• showing 12,000 burst locations and sites of
  special interest. It
• took 22 temporary staff almost a year to survey,
  digitise and
• enter external data.

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Other Methods Of Input

• Laser mapping operated from an aircraft can be
  used to give a quick, accurate reading of the
  height of land. The laser scanner shoots out
  beams at the rate of 5000 10,000 /s, scanning
  the ground at 2m intervals. The time taken for
  the beam to travel back to the plane is taken.
  The height of the aircraft above ground is
  simultaneously measured using GPS satellites to
  give measurements of the relief of the land. A 3D
  computer model can then be created.

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Uses Of GIS Utility Industries

• Used to determine the location of pipes or cables
  above and below ground.
• Can also be used to decide the best locations for
  placing new pipes or cables
• E.g. British Gas use a GIS to document the
  location, depth, size and maintenance records for
  their pipes, for the entire country.

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Uses Of GIS - Business

• Marks and Spencer
• Use GIS to help them decide where to open new
  stores.
• This is done by analysing customer profiles,
  finding the most fuel efficient delivery routes
  and use GIS to generate What If scenarios to
  assist in decision making.

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GIS The Environment

• Used for
• Collating, displaying and analysing data about
  plagues of locusts.
• Creating a computer model of the Greenland Ice
  Sheet, which simulates how the ice mass responds
  to changes in global climate or sea level.
• Monitoring deforestation over time in the Amazon
  Rainforest, by storing processing data
  collected from satellite imagery.

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Other Uses

• The Police Force
• Displaying maps showing incident locations
• Real Time monitoring of police resources
• Holding the burglar alarm and key holder index
• Holding details of boarding-up services

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The End