Kingdom of Saudi Arabia
Ministry of Higher Education
Al-Imam Muhammad Ibn Saud Islamic University
College of Computer and Information Sciences
Chapter 1: Introduction
IS396:Geographic Information System
Agenda
• What is GIS?
GIS Applications
Components of GIS
• A Brief History of GIS
• Geographically Referenced Data
Spatial Data
Attribute Data
Joining Spatial and Attribute Data
• GIS Operations
WHAT IS GIS?
What is GIS?
Geographical Information
Systems (GIS) are information
systems that capture, store,
manipulate, analyze and display
data that is linked to location.
4
stor
e
Source: ESRI
Terms related to Data linked to location --1
• The adjective geographic refers to the Earth’s surface and
near-surface.
• Spatial refers to any space, not only the space of the
Earth’s surface
• Methods used in GIS are also applicable to other nongeographic spaces, including the surface of other
planets, the space of the cosmos, and the space of
the human body that is captured by medical images
• Geospatial implies a subset of spatial applied specifically
to the Earth’s surface and near-surface
Terms related to Data linked to location --2
• Georeferenced or geospatial data (sometimes called
geographically referenced data) are data that describe
both the location and the characteristics of spatial
features on the Earth.
• Example of spatial feature includes road, land parcels,
and vegetation stands on the Earth’s surface.
•
Land parcels with Single Family Residential, Medium Density Residential, and Parks
zoning classifications (Source : ESRI)
Where GIS stands ?
GIS definitions for different groups
Do you
remember
the story of
Blind men
and an
elephant
8
GIS definitions for different groups
• A container of maps in digital form.(the general public)
• A computerized tool for solving geographic problems.(decision
•
•
•
•
makers, planners)
A spatial decision support system. (management scientists,
operation researchers)
A tool for revealing what is otherwise invisible in geographic
information(scientist, investigator)
A tool for automatically performing operations on geographic
data thus avoiding tedious/expensive/inaccurate operations
performed by hand (resource managers, planners,
cartographers)
A mechanized inventory of geographically distributed features
and facilities(utility/resource managers, transportation officials)
Specialty of Geographic Information
What Can GIS Do?
• Visualize Data
• Show Relationships among
Multiple Factors
• Detect and Monitor Change
• Make Comparisons among
Political Jurisdictions
• Examine Local Areas
• Visualize Disparities
• Show Densities in Data
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Applications of GIS
Examples of nature of applications
• Resources inventory (what is available at where?)
• Network Analysis (How to get to a place in the shortest amount
of time?)
• Location Analysis (Where is the best place to locate a shopping
mall?)
• Terrain Analysis (What is the danger zone for a natural disaster?
Visibility analysis)
• Spatio-Temporal Analysis (Land use: what has changed over the
last twenty years, and why?)
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Examples of GIS Applications
U.S. Geological Survey National Map
http://nationalmap.usgs.gov
Incident Information System
http://www.inciweb.org/
National Integrated Land System
http://www.geocommunicator.gov/GeoComm/index.shtm
National Weather Service
http://www.weather.gov/gis/
Hurricane Center
http://www.nhc.noaa.gov/
American Recovery and Reinvestment Act of 2009
http://www.recovery.gov
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Example of GIS Applications
U.S. Census Bureau On-Line Mapping Resources
http://www.census.gov/geo/www/maps/
U.S. Department of Housing and Urban Development
http://egis.hud.gov/egis/
National Institute of Justice: crime mapping
http://www.ojp.usdoj.gov/nij/maps/
Federal Highway Administration
http://www.gis.fhwa.dot.gov/gisData.asp
Federal Emergency Management Agency: flood insurance rate map
http://www.fema.gov/plan/prevent/fhm/mm_main.shtm
Precision Farming
http://www.csrees.usda.gov/nea/ag_systems/in_focus/precision_if_crop.html
Components of GIS
Hardware
Software
People
Infrastructure
Component of GIS - Hardware
• GIS hardware is like any other computer (nothing special about
•
•
the hardware)
o keyboard, display monitor (screen), cables, Internet connection
o with some extra components perhaps
• large monitor, disk drive, RAM
• •
maps come on big bits of paper
• need specially big printers and plotters to make map output from GIS
• need specially big devices (digitizers, scanners,...) to scan and input data
from maps to GIS
Component of GIS - Software
• Operating System to run GIS
• Example of popular GIS software
• ESRI (http://www.esri.com)
• Intergraph Corporation (http://www.intergraph.com )
• Autodesk (http://www.autodesk.com )
• Caliper: GIS Software, Mapping Software (http://www.caliper.com )
Component of GIS - People
• GIS users range from technical specialists who design and
maintain the system to those who use it to help them perform
their everyday work.
• The people who use GIS can be broadly classified into two
classes.
1. The CAD/GIS operator, whose work is to victories the map
objects.
2. The use of this victories data to perform query, analysis or any
other work is the responsibility of a GIS engineer/user.
Component of GIS – Infrastructure
• The necessary physical, organizational, administrative, and
cultural environments that support GIS operations.
• The infrastructure includes requisite skills, data standards, data
clearinghouses, and general organizational pattern.
BRIEF HISTORY OF GIS
A Brief History of GIS
1963 : CGIS development Initiated
• Canada Geographic Information System is developed by
Roger Tomlinson and colleagues for Canadian land
inventory.
• The project pioneered much technology and introduced
the term GIS
The Era of Innovation
1963 : URISA established
• The urban and Regional Information Systems Association
founded in the US
• It became point of interchange for GIS innovators
The Era of Innovation
1964 : Harvard Lab established
• The Harvard Laboratory for Computer Graphics (and
spatial analysis) was established at the Harvard Graduate
School of Design (GSD) under the direction of horward
Fisher.
• In 1966 SYMAP, the first raster GIS was created by
Harvard Researcher
A surface interpolated with SYMAP
The Era of Innovation
1967 : DIME developed
• Dual Independent Map Encoding (DIME) was an
encoding scheme developed by the US Bureau of the
Census for efficiently storing geographical data
• The file format developed for storing the DIME-encoded
data was known as Geographic Base Files (GBF)
• The US Bureau of Census used DIME-GBF used for 1970
and 1980 census.
• TIGER files replaced DIME files for the 1990 and
subsequent censuses.
The Era of Innovation
1969 : ESRI Inc. formed
• Jack Dangermod, a student from Harvard Lab, and his
wife Laura form Environmental Science Research
Institute (ESRI) as a privately held consulting group to
undertake projects in GIS.
• The business began with $1100 from their personal
savings operating from California.
The Era of Innovation
1969 : Intergraph Corp. formed
• Jim Meadlock and four others that worked on guidance
systems for Saturn rockets form M&S Computing, later
renamed Intergraph
GeoMedia
Dynamic Segmentation results using GeoMedia
The Era of Innovation
1969 : “Design with Nature”published
• Ian McHarg’s book was the first to describe many of the
concepts in modern GIS analysis, including the map
overlay process
The Era of Innovation
1972 : Landsat 1 Launched
• Originally named ERTS (Earth Resources
Technology Satellite), this was the first of
many major Earth remote sensing
satellites to be launched
• Served as a stabilized, Earth-oriented
platform for obtaining information on
agricultural and forestry resources,
geology and mineral resources, hydrology
and water resources, geography,
cartography, environmental pollution,
oceanography and marine resources, and
meteorological phenomena.
The Era of Innovation
1974 : AutoCarto 1 Conference
• Held in Reston, Virginia, this was the first in an important
series of conferences that set the GIS research agenda
The Era of Innovation
1977 : Topological Data Structures
Conference
• Harvard Lab organizes a major conference
• Odyssey GIS was the first vector GIS developed by the
Harvard Laboratory for Computer Graphics and Spatial
Analysis in the mid-1970's
The Era of Innovation
1981 : ArcInfo Launched
• ArcInfo was the first major commercial GIS software
system.
• Designed for minicomputers and based on the vector and
relational database data model, it set a new standard for
the industry
• In 1987, ArcInfo was launched for PCs
The Era of Commercialization
1984 : “Basic Readings in Geographic
Information Systems”published
• This collection of papers published in book form by Duane
Marble, Hugh Calkins, and Donna Peuquet was the first
accessible source of information about GIS
The Era of Commercialization
1985 : GPS operational
• The Global Position System become operational
• It is today a major source of data for navigation,
surveying, and mapping.
The Era of Commercialization
1986 : “Principles of Geographic Information System
for Land Resources Assessment”published
• Peter Burrough’s book was the first specifically on GIS. It
quickly became the worldwide reference text for GIS
students
The Era of Commercialization
1986 : MapInfo Corp. formed
• MapInfo software develops into first major desktop GIS
product. It defined a new standard for GIS products,
complementing earlier software systems.
• MapInfo for Windows replaced MapInfo for DOS in 1990
The Era of Commercialization
1987 : International Journal of Geographic
Information Science introduced
• Terry Coppock and others published the first journal on
GIS.
• The first issue contained papers from the USA, Canada,
and German
The Era of Commercialization
1987 : Chorley Report
• “Handling Geographic Information’’ was an influential
report from the UK government that highlighted the value
of GIS.
The Era of Commercialization
1988 : GISWorld begins
• GISWorld, now GeoWorld, the first worldwide magazine
devoted to GIS was published in the USA
The Era of Commercialization
1988 : TIGER announced
• TIGER (Topologically Integrated Geographic Encoding
and Referencing), a follow-on from DIME, is described by
the US Census Bureau.
• Low cost TIGER data stimulates rapid growth in US
business GIS
The Era of Commercialization
1988 : US and UK Research Centers
announced
• Two separate initiatives, the US NCGIA(National Center
for Geographic Information and Analysis) and the UK RRL
(Regional Research Laboratory) show the rapidly growing
interest in GIS in academia.
The Era of Commercialization
1991 : Big Book 1 published
• Substantial two volume compendium ‘‘Geographical
Information Systems; principles and applications’’ edited
by David Maguire, Mike Goodchild and David Rhind
documents progress to date.
The Era of Commercialization
1992 : DCW released
• The 1.7 GB Digital Chart of the World, sponsored by the
US Defense Mapping Agency (now NIMA) is the first
integrated 1:1 million scale database offering global
coverage
• Freely available as of 2006, although it has not been
updated since 1992
The Era of Commercialization
1994 : Executive Order signed by
President Clinton
• Executive Order 12906 leads to creation of US National
Spatial Data Infrastructure (NSDI), clearinghouses and
Federal Geographic Data Committee (FGDC)
The Era of Commercialization
1994 : OpenGIS consortium born
• The OpenGIS Consortium of GIS vendors, government
• agencies and users is formed to improve interoperability
The Era of Commercialization
1996 : Internet GIS products introduced
• Several companies, notably Autodesk, ESRI, Intergraph,
and MapInfo release new generation of Internet-based
products at about the same time. Leads to rapid
expansion of GIS involvement
The Era of Commercialization
1996 : MapQuest
• Internet mapping service launched, producing over 130
million maps in 1999.
• Later AOL purchases for $1.1 billion.
The Era of Commercialization
1999 : GIS day
• Day attracts over 1.2 million global participants who share
an interest in GIS
The Era of Commercialization
2000: GIS has 1 million users
• GIS has more than 1 million core users and perhaps 5
million casual users of GI
The Era of Exploitation
2005
• Google Earth is a virtual globe, map and geographical
information program that was originally called
EarthViewer 3D created by Keyhole, Inc, a Central
Intelligence Agency (CIA) funded company acquired by
Google in 2004
• Google Earth released in 2005 for PCs
• As of October 2011, Google Earth has been downloaded
more than a billion times
• Source : http://en.wikipedia.org/wiki/Google_Earth
2004-2011: Business Situation
According to a just released study
by Daratech, (www.daratech.com)
an industry analyst group
specializing in GIS/Geospatial
market dynamics, sales of
GIS/Geospatial software, services
and data grew a robust 10.3% in
2010 to US$4.4 billion
Summary : A Brief History of GIS
Canada Land Inventory and the subsequent development of the Canada
Geographic Information System in the early 1960s
Computer mapping at the University of Edinburgh, the Harvard
Laboratory for Computer Graphics, and the Experimental Cartography Unit
in the 1960s and 1970s
Publication of Ian McHarg’s Design with Nature and its inclusion of the
map overlay method for suitability analysis in 1969
Introduction of an urban street network with topology in the U.S. Census
Bureau’s DIME (Dual Independent Map Encoding) system in the 1970s
Mainstream use of GIS in the 1990s
Two recent trends in GIS: (1) integration with other geospatial data such
as satellite images and GPS data, and (2) linkage with Web mapping, Web
service, social media, and cloud computing
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GEOGRAPHICALLY REFERENCED DATA
Nature of Geographically Referenced Data
• Geographically referenced data has two components.
1. Spatial Data
2. Attribute Data
Example of Road
To describe a road, we refer to
1. Its location (i.e. Where it is )
2. Its characteristics (e.g. length, name, speed limit, and
direction
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Figure 1.1
An example of geographically referenced data. The street network is based on a
plane coordinate system. The box on the right lists the x- and y-coordinates of
the end points and other attributes of a street segment
GIS Data Components
• Spatial (geographic) – where?
• Attribute (descriptive) – what?
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Source: TPL Greenprinting Analysis Unit
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Coordinate System
Geospatial data are geographically referenced.
Two spatial reference systems used in GIS are
-the geographic coordinate system
-the projected coordinate system.
Projection connects the two spatial reference systems.
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Data Model
The data model define how spatial features are
represent in GIS
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Vector Data Model
The vector data model uses points and their x-, ycoordinates to represent discrete features.
The vector data model may be georelational or
object-based, may or may not involve topology, and
may include simple or composite features.
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Figure 1.3
The vector data model uses x-, y-coordinates to represent point features
(a), and the raster data model uses cells in a grid to represent point
features (b).
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Figure 1.4
Point, line, and area features.
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Figure 1.5
A Triangulated irregular network(TIN) example
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Figure 1.6
Dynamic segmentation allows rest areas, which are linearly
referenced, to be plotted as point features on highway routes in
Washington State.
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Raster Data Model
The raster data model uses a grid and grid cells to
represent continuous features such as elevation and
precipitation.
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Figure 1.7
A raster-based elevation layer
Important Terminology
• Georelational data model: uses split system to store
spatial data and attribute data
• Object-based data model: store spatial data and
attribute data in a single system.
• Topology: is the spatial relationships between features.
Such as
1- Two lines meeting perfectly at a point
2- A directed line having an explicit left and right side.
Important Terminology
• Coverage: Topological data.
• Shapefile: non topological data.
• Triangulated irregular network(TIN) : the terrain with a
set of non overlapping triangles, is made of
nodes(points),edges(lines).
• Regions data model: allows regions to overlap and to
have spatially disjoint components, is build with polygons.
• Dynamic segmentation model: linear measure system
is built on top of linear features.
GIS OPERATIONS
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GIS Operations
GIS activities can be grouped into
1. Data acquisition
2. Attribute data management
3. Data display, Data exploration
4. Data analysis, and
5. GIS modeling.
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Figure 1.8
A vector-based overlay operation combines spatial data and
attribute data from different layers to create the output.
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Figure 1.9
A raster data operation with multiple rasters can take advantage of
the fixed cell locations.
References
• Introduction to Geographic Information Systems by Kang-
tsung Chang.
• Geographic Inforamtion Systems and Science by Paul A.
Longley and et al