Introduction to Geographic
Information Systems
Environment and Land Planning Applications
Prof. Maria Antonia Brovelli
Politecnico di Milano
Polo Regionale di Como
Definition of Information System
An information system is an organized set of
procedures
human resources
material resources
used to
gather
store
process
communicate
information needed by an organization to manage its
operational and government activities.
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Geographic Information Systems
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Geographic Information System
We define GIS (Geographic Information System) as a structure
constituted by a powerful set of instruments and technologies
committed to acquire, store, manage, transform, analyze and visualize
georeferenced spatial data.
Georeferenced information: every document or event referred to a
particular portion of Earth’s surface is an example of georeferenced
information
Geospatial information: every document or event that is also
represented from a cartographic point of view or by maps or
aerial/satellite images is an example of geospatial information
Often the two terms (georeferenced and geospatial) are used as
synonyms.
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Geographic Information Systems
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Geographic Information System
Spatial or geographic data represent REAL WORLD PHENOMENA and they
are characterized by:
their POSITION in space with respect to a reference and coordinate
system
NON-SPATIAL ATTRIBUTES (color, temperature, etc…)
mutual SPATIAL RELATIONS (topological, directional, distance
relations)
The definition of a GIS contextually requires the definition of its objectives
and methods
 GIS OBJECTIVES means the set of results pursued at the moment
of the definition and creation of the GIS itself
 GIS METHODS means the set of operators, coded in an abstract
form, which allows to accomplish such objectives
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Geographic Information Systems
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Definitions ...
a) GIS definitions based on the concept of Database
“A database system in which most of the data are spatially indexed, and
upon which a set of procedures operated in order to answer queries about
spatial entities in the database”
Smith T.R., S. Menon, J.L. Starr, and J.E. Estes, 1987.Requirements and principles for the implementation and
large-scale geographic information systems. International J. of Geographical Information Systems, 1: 13-31.
construction of
“any manual or computer based set of procedures used to store and
manipulate geographically referenced data”
Aronoff S., 1989. Geographic Information Systems: A Management Perspective. WDL Publ., Ottawa, Canada.
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Geographic Information Systems
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Definitions ...
b) GIS defined as a structure constituted by a set of
instruments and technologies
“a powerful set of tools for collecting, storing, retrieving at will,
transforming and displaying spatial data from the real world”
Burrough P., McDonnel A. (1998) – Principles of Geographical Information Systems – Oxford University Press,
Oxford
“A system for capturing, storing, checking, manipulating, analysing and
displaying data which are spatially referenced to the Earth ”
Department of Environment (DoE), 1987. Handling Geographic Information. HMSO, London, 1988
c) GIS definitions based on organizational aspects
“a decision support system involving the integration of spatially referenced data in
a problem solving environment”
Cowen D.J., 1988. GIS versus CAD versus DBMS: what are the differences? Photogrammetric Engineering and
Remote Sensing, 54: 1551-1554
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Geographic Information Systems
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Components of a Geographic
Information System
•Data (geographic information models and structures)
•Organizational structures and work methods
•Software components
•Hardware components
computer
digitizer
plotter
printer
CD/DVD reader/writer
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Geographic Information Systems
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M.A.Brovelli - Introduction to
Geographic Information Systems
Functionalities
of a GIS engine8
a) Conceptual models
of the world
COMPLETELY DEFINED and
DEFINABLE
OBJECTS/ENTITIES
REALITY
NOT COMPLETELY DEFINED
and DEFINABLE SPATIAL
ENTITIES
CONTINUOUS and SLOW
VARIATIONS
SAMPLING AND/OR INTERPOLATION
(SCANNED IMAGES,
INTERPOLATED SURFACES)
b) Data models
THE WORLD CONSISTS OF
SETS OF DISCRETE OBJECTS,
WITH ATTRIBUTES AND
MUTUAL RELATIONS
OBJECTS
FILTERING
THE WORLD CONSISTS OF
CONTINUOUS AND SLOWLY
CHANGING FIELDS
c) Representation
OBJECTS ARE FORMED OF
SIMPLER ENTITIES (ATOMIC
ENTITIES), THEIR
ATTRIBUTES AND THEIR
MUTUAL RELATIONS
DISCRETIZED SURFACES
CONTINUOUS
MATHEMATICAL
FUNCTIONS
M.A.Brovelli - Introduction to
Geographic Information Systems
CONTINUOUS NONDIFFERENTIABLE
MATHEMATICAL
EQUATIONS
(FRACTALS, STOCHASTIC
9
SURFACES)
GIS environment/landscape
planning applications
• Environment/landscape condition: analysis and
control
Human activities planning
Environment/landscape-oriented actions
• Research in environment/landscape planning fields
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Geographic Information Systems
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Environment/landscape planning
GIS purposes - 1
• Production of
geographic
archives,
thematic maps
and
inventories
(both local or
accessible
through
the
Internet)
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Geographic Information Systems
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Environment/landscape planning
GIS purposes - 2
Examples:
 automate the elaboration
Environmental Assessment
of
an
 automate
the
formation
of
instruments to support eco-planning
and land planning government;
 priorities selection and environmental
policies
adjustment
to
create
environmental Action Plans.
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Geographic Information Systems
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Environment/landscape planning
GIS purposes - 3
 Scientific research in
environment / landscape
planning fields:
3D models of the GRASS GIS: meteorological
analysis (Steve Hall, Markus Neteler)
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Geographic Information Systems
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Scales for GIS applications
• Microlocal (e.g.: quarry control)
• Local (e.g.: drainage interventions)
• Regional (es: avalanche control)
• National (es: disaster forecasting)
• Continental/Global
 obviously the GIS will have different resolutions / detail
levels
What is the scale of a GIS?
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Geographic Information Systems
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Outline of an environmental GIS
ENVIRONMENTAL
DATA
(GEOREFERENCED
OR NOT)
• Data modeling in
environmental GIS
• Basic functionalities
• Specific functionalities
BASIC
FUNCTIONALITIES
SPECIFIC
FUNCTIONALITIES
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Geographic Information Systems
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Environmental GIS data
• Vector and raster maps
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Geographic Information Systems
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Example: download from
http://www.cartografia.regione.lombardia.it/geoportale
DEMO:
try by
yourself!
M.A.Brovelli - Introduction to
Geographic Information Systems
your
request
succeeded!
check your
17
email box
Install
Quantum
GIS on
your
computer;
in the
example
Quantum
GIS 1.6
Where find I Quantum GIS?
http://www.qgis.org/wiki/Download
Open your
vector
data
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Geographic Information Systems
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Geographic Information Systems
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Geographic Information Systems
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Geographic Information Systems
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set transparency
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Geographic Information Systems
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Environmental GIS data
• Field observations
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Geographic Information Systems
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Environmental GIS data
• Orthoimages and remotely
sensed images
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Geographic Information Systems
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Environmental GIS data
• Digital Surface Models
(DSM) and Digital Terrain
Models (DTM)
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Geographic Information Systems
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Environmental GIS data
• Primary thematic maps
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Geographic Information Systems
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Environmental GIS data
• Derived thematic maps
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Geographic Information Systems
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