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