GISGeographical Information

Systems

What is GI

Geographical Information

Any information that has a spatial element is Geographical.

That is any information that can be located on a map.

Using GI to solve problems – Cholera Epidemic

Original map by Dr. John Snow showing the clusters of cholera cases in the London epidemic of 1854

1854 London – Cholera (after Dr. John Snow)

Source: ESRI

“…a digital map, data located on the map, and a software application (GIS) that links the two together”

Diana Freeman (2004)

Slide from: Alan Parkinson

GIS-what makes it so successful?

Tool for gathering, organizing, analyzing spatial data to produce geographic information

• With GIS we can describe an object in two interrelated ways:

Attributive information:What it is?

Kind: OakHeight: 15mAge: 75

Information about its location: Where?

51°N, 112°W

GIS database• Spatial (location) data and

attributive (describing) data are stored into the GIS relational database

Kind: OakHeight: 15 mAge: 75

Attr.data

51°N, 112°WSpatial data

Where is GIS?

Where is GIS?

Coastal & Marine Protection

Agriculture

Defence

Search & RescuePort & Airport Management

Land Registry

Telecommunications

Aviation

Retail

Education

Parks & Recreation

Health

Museum

Economic Development

Government

Utilities

Security

Banking

Insurance

Waste Collection

Landscape Planning

Asset Management

Street LightingFacility ManagementTourism

Public Safety

Engineering

Nature Conservation

Logistics

Town Planning

Highways

National Mapping

Surveying

ForestryMiningPetroleum

GIS is basedon layers ofInformation

Properties

Census Data

Health Statistics

Utility Networks

Policy Holders

Land Ownership

Flood Risk

Rivers/Canals

Locations

CCTV Coverage

Building Plans

Assets

Road Network

Woodland

Geology/Soils

Terrain

Display features on a map

Identify features within a target area

Trigger activities based on location

Show which features are related

Perform comparative time-based analytics

Create thematic maps Show clusters and hotspots

Change the attributesof a feature

Change location of a feature

Perform proximity analysis

Analyse where to reallocate resources

View locations over a satellite image

Answer what-if scenarios

Find a route from A to B across a network

Find a route from A to B considering impedances

Value of GIS - Spatial Analysis