Introduction to GIS for the Purpose of Practising PGIS
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Transcript of Introduction to GIS for the Purpose of Practising PGIS
Support the spread of “good practice” in generating, managing, analysing and communicating spatial information
Introduction to GIS for the Purpose of Practising PGIS
Introduction to GIS
By: Jon Corbett and Kasondra White
Unit: M12U01
Introduction
• Participatory GIS (PGIS)
• Documenting, presenting and protecting local knowledge
• What is a GIS?
• Representing data
• Quantum GIS
• Participatory mapping and GIS
What is a GIS?
• GIS systems:– capture;– store;– analyse;– manage; and– present geographic data.
What is a GIS?
• GIS packages work with:– maps;– remote sensing;– land surveying;– aerial photography;– databases;– other tools.
What is a GIS?
• GIS applications allow users to:– create queries;– analyse spatial information;– edit data and maps;– present results.
• Information can be presented:– in a map;– in a textual form.
What is a GIS?
• Geospatial data:– information related to a location that can be
expressed using coordinates
• GIS can be used for:– creating maps– visualising the relationship between places
and events– searching for geospatial associations– analysing geospatial data
Representing data
• Kinds of questions that GIS can answer:– What is located at a given point?– What kinds of changes have occurred?– What kinds of patterns exist?– What would happen if some kind of a change
were to occur?
Points, lines and polygons• Points
– one spot on a map
– represent exact locations
• Lines
– string of points
– can be measured
for distance
• Polygons
– enclosed area
– defined by often
complex boundaries
Data layers
• Features are displayed through data layers
• Contain thematic data
• Layers can be:– turned on or off– placed on top of or below
one another
• Multiple layers can be open at one time
Quantum GIS
• Open source – freely available– supported by a community of programmers
and technicians
• User-friendly
The graphical user interface (GUI)
• Simplifying interactions with software
• Uses:– clickable symbols– text
• Understanding GUI functions is an important part of learning GIS
The graphical user interface
The toolbar
Participatory mapping and GIS
• Does GIS fit with the community’s vision?
• Does GIS directly address mapping needs?
• Is GIS anti-participatory?– expertise required– may require technicians from outside the
community
Participatory mapping and GIS
• Practitioners of participatory development should avoid technologies that are:– complex– expensive– time-consuming
• May, however, still be useful
• “Chauffeur-driven” systems
GPS• Displays points collected through a
Global Positioning System (GPS)• Captures coordinates of locations
of interest• Points can be uploaded and
displayed• Useful for depicting locations or
boundaries