Transcript Document

GEOGRAPHIC INFORMATION SYSTEMS
PRESENTATION 1
to
Natural History Division, Institute of Jamaica
By Suzanne Davis & Alfreco Johnson
Natural History Division, Institute of Jamaica
January 2003

GEOGRAPHIC
INFORMATION SYSTEMS
(GIS)
GIS:- a computer-based tool used and
managed by people to efficiently capture,
store, integrate, analyze and display spatial
(geographically referenced) data & associated
attribute data.
Key components:
1.
2.
3.
4.
5.
Hardware (computer)
Software (storage, editing, analysis and display
programmes)
* Data (spatial and descriptive or attribute)
People (applicators of tool to problems)
Procedures (based on plans/protocols/models
unique to each organization)
GIS Characteristics
 A powerful mapping system that links locations
to attribute data so you can:
 Present different types of information (ecological,
social, educational, etc.) as maps
 Analyze
locations
and
associated
data/information
 Easily and efficiently update of spatial information
(maps)
 Integrate maps with information from a variety of
sources
Why Use GIS?
 Offers advanced data management capabilities for
handling complex or various datasets linked to
locations
 Allows improved research and planning activities
by integrating data and information from different
sources to produce a ‘wholistic’ picture.
 Facilitates colourful media presentations for easier
interpretation of technical data & information by
technical (e.g. scientists) and non-technical
personnel (e.g. managers, policy-makers)
Spatial Data
 SPATIAL DATA: a precise geographic location
 a distance or length referenced
by geographic coordinates or
 an area that has measured
boundaries referenced by geographic
coordinates.
points
lines
polygons
Examples: maps & charts, surveyor records, building
plans and satellite images
Benefits of Spatial Data
 Databases for taxonomic collections & field data have
added value if the records include spatial data.
 Data on location or space is critical to understanding
ecological patterns or natural phenomena
If the same collecting methodology is used in the same
geographic location periodically, it is assumed that
detected trends or changes in wildlife occurrence and
distribution reflects trends or changes that may have
taken place in that environment or in ecological
interactions.
 Spatial databases allow more efficient forecasting for
businesses, land developers, education and research
personnel, etc.
Applicability of a GIS
 GIS can be used in just about any situation
where there is a spatial component and the
composite features of the same space can be
separated to form layers.
 What is a Map Layer?
A layer is an abstraction of a single feature from
a spatial area represented on a map. This is
where one feature is pulled from a geographic
area and made to stand alone.
Some Sectors in which GIS is
widely used

Transportation (Highway system)
Whether monitoring bus systems and road conditions, finding
the best way to deliver goods and services, tracking fleet
vehicles, or maintaining transportation networks

Education
A GIS allows students and researchers to ask and answer
geographic questions by designing and analyzing maps using
user-selected criteria.

Engineering
GIS provides the pipeline operator with improved capability to
manage pipeline integrity, improved efficiencies in pipeline
operations, and improved response to business development
opportunities.

Communication
Location-based services combine GIS applications with easyto-use mobile devices to provide information wherever and
whenever it is needed.
GIS Sectors (cont.)
 Business
Used in banking and insurance for more precise
targeting of customers in marketing exercises
 Health and Human Services
Understanding issues ranging from epidemiology to
access to healthcare providers requires
understanding the geographic context of health
issues.
 Natural Resources Monitoring & Environmental
Management
Geography provides the framework to acquire,
develop, and interpret the complex spatial and tabular
datasets used for mining and the earth sciences.
Mapping, spatial concepts, and time/space operations
technology is absolutely essential to effective mining.
Example of GIS Use in Transportation
Land Coverage of the United States
Major Highway Coverage
(Highway Layer)
Highway layer superimposed with
land coverage
United States Cities locations
superimposed with highways
Who Uses GIS in Jamaica?
 Individuals
 Government agencies (e.g. Forestry Department,
National Environment & Planning Agency, Urban
Development Corporation)
 Non-government organizations (e.g. Jamaica
Conservation Development Trust, the Nature
Conservancy – Jamaica)
 Teaching & research institutions (e.g. University of
Technology, University of the West Indies)
 Business enterprises & consultancies (e.g. Spatial
Innovision
Processing of Maps
There are Two primary stages in the
processing of Maps:
 Digitizing and Formatting
 Adding Attributes and Values
Digitizing and Formatting
Digitizing is the process of assigning
digital coordinates by physically or
automatically tracing hard copy
documents. Primarily used for converting
paper maps or aerial photos into digital
form.
Picture of a digitizing board


Map or image is secured to board and important
reference points are matched
Important features of map are then traced with
digitizing mouse by clicking the mouse
Digital references are then made to all
polygons in digitized image
Further formatting of the digitized
image is done
Finished Product
Adding Attributes and Values
of Features
Attributes are descriptive characteristics of
the features of a spatial entity.
Attributes take the form of:
Measurements – height, distance, intensity, etc
Classifications – Acidic, alkaline, residential,
etc.
Quality – good, bad, satisfactory, A, B, C, etc
GIS Software
 ArcInfo
 Arc View
 Most comprehensive
GIS available
 Defines spatial
relationships
between connecting
or adjacent
coverage features
 Provides GIS data
creation (e.g.
digitizing), updating,
mapping, querying and
analysis
 Most popular desktop
GIS and mapping
software
 Provides data
visualization,
querying, analysis,
and integration
capabilities along
with the ability to
create and edit
geographic data.
Africa
Countries and lakes represented as polygons
& rivers represented as lines
Africa
Northern rivers selected (in yellow)
Africa
Result of a query to find out what countries the
northern rivers traverse (in yellow)
Africa
Country of Gabon Selected (in yellow)
Africa
Countries within 1000 miles of Gabon having rivers
The End
Thank You