Computerised cartography involves using computer hardware and software to perform mapmaking and cartographic functions. A geographic information system (GIS) is a system of computer software, hardware, and data that allows users to visualize, manipulate, analyze and display spatial data. A GIS integrates these components to help users manage, analyze and present information tied to a spatial location. It allows users to ask questions of data, get interactive maps and reports, and combine data from different sources for spatial analysis and modeling.
1. COMPUTERISED CARTOGRAPHY
-- performing cartographic functions by means computer
hardware and software
CARTOGRAPHY
-- art and science of map making
A map represents geographic features or other spatial
phenomena by graphically conveying information about
locations and attributes
MAP
•Map(graphic) information * only graphic data is available
and retrieval * networks are not defined.
•Map publication * spatial relationship not defined
Computer Assisted Mapping
INTRODUCTION
2. Graphics are holistic:
“a picture says more than a thousand words...”
“First road left, then
cross the railroad and
continue until you
cross the river, then
the first right and right
again on the
crossroads...”
Introduction
Why Use Graphics
3. Why GIS?
• 70% of the decisions, we make are
based on geographical
considerations
• Ability to assimilate spatial and non-
spatial data
• Visualisation Impact
• Sharing of Information
• Analytical Capability in a spatial
context
4. GIS is a System of computer software, hardware
and data, and personnel to help manipulate,
analyze and present information that is tied to a
spatial location –
• 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 GIS
Geographic Information Systems
A Definition of GIS
5.
6.
7.
8. What is Not GIS ?
• GPS – Global Positioning System
• A static map – paper or digital
– Maps are often a “product” of a GIS
– A way to visualize the analysis
• A software package
9. • GIS handles SPATIAL
information
– Information referenced by its location in
space
• GIS makes connections between
activities based on spatial
proximity
9
Why is GIS unique?
10. Components of GIS
A working GIS system
integrates these five key components:
➢ Hardware
➢ Software
➢ Data
➢ People
➢ Methods
11. WHY GIS ?
• To inventory and monitor
resources
• To test the sensitivity of our
analysis assumptions
• To simulate potential impacts of
management alternatives
• To make the map the 2nd time,
the 50th time, the 100th time...
12. • GIS improves efficiency
• GIS identifies opportunities
• GIS improves decisions by
providing needed tools and data
How Does GIS
Provide Benefit?
13. Uses of a GIS
• Mapping geographical
characteristics for analysis
• Modeling alternative processes
for management plans
• Managing a utility’s assets
• Monitoring changes in
environmental factors
14.
15. Spatial Data
• Estimates are that 80% of all
data has a spatial component
– Data from most sciences can be
analyzed “spatially”
16.
17.
18.
19. Two Ways to Input and Visualize Data
• Raster – Grid
– “pixels”
– a location and value
– Satellite images and aerial
photos are already in this
format
• Vector – Linear
– Points, lines & polygons
– “Features” (house, lake, etc.)
– Attributes
– size, type, length, etc.
Real world
20.
21.
22.
23.
24.
25.
26.
27. • A method to
visualize, manipulate,
analyze, and display
spatial data
• “Smart Maps”
linking a database to
the map
28. Data Capture Sources
• Digitizing from paper maps
• Scanning
• Traditional surveying
techniques
• Paper records & field notes
• Photogrammetry
• Remote sensing
• GPS