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1 Introduction to GIS GIS technology
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Introduction to GIS
GIS technology
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GIS Technology
What is GIS
Components of GIS
Functions of GIS
Benefits of GIS
Real World Applications
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A Geographic Information System (GIS) is a
collection of computerized maps and databases
that are linked together for the purpose of
storing, retrieving, managing and analyzing
information.
What is GIS?
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A GIS is a technological field that incorporates
geographical features with tabular data in order to
map, analyze, and assess real-world problems. The
key word to this technology is Geography – this
means that some portion of the data is spatial. In
other words, data that is in some way referenced to
locations on the earth.
What is GIS?
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“In the strictest sense, a GIS is a computer system
capable of assembling, storing, manipulating, and
displaying geographically referenced information,
i.e. data identified according to their locations.
Practitioners also regard the total GIS as including
operating personnel and the data that go into the
system. “USGS”
What is GIS?
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Interpretation of the words
GIS: A particular form of information system
applied to geographical data
A system: A group of connected entities and
activities which interact for a common purpose
An information system: A set of processes,
executed on raw data, to produce information
which will be useful for decision making
Geographical data: Spatially referenced data sets
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What Is a
Geographic
Information
System?
…What is GIS?
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Sample overlay
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GIS (Describing Our World)
We can describe any
thing of our world in
two ways:
Attribute Information: What is it?
Species: Oak Height: 15m
Age: 75 Yrs
Location Information: Where is it?
51°N, 112°W
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Geographic Information Systems are
driven by the data linked to the maps.
Forget about Maps!
Databases 80%
Maps 20%
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Approximately 80% of ALL data stored is
related to a geographic location.
Did you Know?
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GIS – a system
A GIS is an information system
Its common purpose: decision making for
managing use of land, resources, or any spatially
distributed activities or phenomena
It processes raw geographical data
It produces information for decision making of
spatial activities
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The technical concerns
“Spatial is special” Geospatial – subset of “spatial” (on earth)
Technical matters
Multi-dimensional
Voluminous
Projected onto a flat surface
Special methods of analysis
Large variety of geographical information
Updating is complex and expensive
Visualisation and map making requires large amount of data
GISystems, GIScience and GIStudies, GIServices GISystems
Emphasis on technology and tools
Emphasising infrastructure
GIScience
Emphasising principle and theory
Fundamental issues raised by the use of GIS and related technologies
Spatial analysis
Map projections
Accuracy
Scientific visualization
GIStudies
Systematic study of the use of geographic information.
Emphasising data and data mining
GIServices
Emphasising socio-economic service
What can a GIS do?(5W)
Condition (What is it...)
Location (Where is it...)
Trend (What has changed...,What trends are occuring)
Pattern (What is the pattern..., What is nearby?)
Modeling (What if...)
Why is GIS Important?
Provides a consistent framework for
integrating spatial and other kinds of
information within a single system (ideal for
interdisciplinary work).
Permits manipulation and display of
geographical (digital) data in new ways.
Makes connections between activities based
on geographic location.
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Why Use GIS?
GIS is not.....simply a computer system for
making maps, although it can create maps at
different scales, in different projections, and
with different colors.
GIS is much more than mapping software. Maps
are only one of three views of a GIS. When
deployed with a clear strategy, GIS is a
technology that can change an organization
fundamentally and positively.
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Three Views of a GIS
A geographic information system supports several
views for working with geographic information.
Geodatabase view
Geovisualization view
Geoprocessing view
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Three Views of a GIS
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Where is a GIS from?(Origin of GIS)
Geography
Cartography
CAD and computer graphics
Surveying and photogrammetry
Remote sensing and space technology
…..other Systems
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GIS
CAD
CAC
RS DBM
:Computer –Aided Designـ أنظمة التصميم بمعونة الحاسب 1
تتيح الوصول إلى قواعد البيانات ولكن بشكل محدود
.إمكانياتها التحليلية محدودة
:Computer Cartographyـ الأنظمة الكرتوغرافية 2
. topologyبنية المعلومات فيها بسيطة وتفتقر إلى العلاقات المكانية
.قدراتها التحليلية محدودة
Database management systemsـ أنظمة إدارة قواعد البيانات3
DBMS):)
تخزن وتجمع وتعالج البيانات الوصفية
.إمكانياتها الرسومية محدودة وتفتقر إلى إمكانية التحليل الجغرافي
:Remote sensing systemsـ أنظمة الاستشعار عن بعد 4
raster dataتجمع وتخزن وتعالج البيانات النقطية
vector) الشعاعية تفتقر هذه الأنظمة إلى القدرة على معالجة البيانات
data )
.إمكانية ربطها مع البيانات الوصفية محدودة
GIS & Others Science and Technology
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A brief history of GIS
The era of innovation
1960s – 70s
The era of commercialization
1980s – 90s
The era of exploitation
The 21st century
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GIS Technology
What is GIS
Components of GIS
Functions of GIS
Benefits of GIS
Real World Applications
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Components of a GIS
Data People
Hardware
Software
Digitizer, scanner,
PC, etc.
Scientists, GIS
technicians, etc.
Raster, vector, x,y
tables, etc.
ArcMap, IDRISI,
MapInfo, etc.
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1. Hardware
Computer
Scanner
Printer Digitizer
Plotter
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1. Hardware
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2. GIS– Software
ESRI:Products, used by 77% of GIS
professionals. ArcView, ArcGIS, ArcSDE.
IDRISI: Proprietary GIS product developed by
Clark Labs.
Geomedia: (INTERGRAPH), Products, used by
18% of GIS professionals.
Autodesk: World (Autodesk)
Mapinfo Pro: Products, used by 20% of GIS
professionals
GeoConcept: (Geoconcept)
GIS Data
Models
Attribute Data Spatial Data
Vector Data
Point, Polyline,
Polygon
Type of Storing:
Shape file:.shp
Personal &File geodatabase: . mdb, gdb
Coverage: dwg, dxf, dgn
Raster Data
Pixel:
Picture Element
Type of Storing:
.jpeg,img,tiff,
gif,ecw,bmp,..
3. GIS Data
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3. Spatial Data :
Geographic coordinates
Tabular attributes
•GIS stores and
manages geographic
data in a number of
formats. The two
basic data models
that ArcGIS uses are
Vector, Raster.
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3. Spatial Data
Spatial data can be in either vector or raster format:
Vector format is used when a feature has
shape and size (can be point, line, or
polygon) and is stored in a shapefile (*.shp)
Raster format is used when data has no
distinct shape (e.g. rainfall, wind,
temperature, “greenness”, etc.) and is often
stored as an image file (*.img)
Vector vs. Raster Data Representation
Point
Line
Polygon
Vector Raster
Raster data are described by a cell grid, one value per cell
Zone of cells
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Vector data
Points are pairs of x,y coordinates.
Lines are sets of coordinates that define a shape.
Polygons are sets of coordinates defining
boundaries that enclose areas.
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3.1 Data Types :Vector Data
Points, Lines and Areas represent entities
Points - City, Tree
Lines - River, Road
Areas - Forest, Lake
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Points
Zero-dimensional - represents a site
Lines
One-dimensional – has length but no
width
Polygons
Two-dimensional – an area
Volumes
Three-dimensional – occupies an area
and has a vertical component
Data Types :Vector Data
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Point
A point object has neither length nor breadth nor depth.
May be used to indicate spatial occurrences or events,
and their spatial pattern.
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Line
A line object has length, but not breadth or depth.
Used to represent linear entities that are frequently built together into networks.
Also used to measure distances between spatial objects.
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Area
An area object has two dimension, length and breadth, but not depth.
Represents enclose areas of natural or artificial objects.
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Volume
A volume object have length, breadth and depth.
Used to present natural (e.g. mine bodies and
buildings) or artificial objects.
Vector data formats
Vector data formats for storing point, line, and
polygon features. These formats include:
Shapefiles
Geodatabases
Coverages(cad files ,dgn)
Event tables
Triangulated Irregular Networks (TINs)
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Personal Geodatabase
Feature data set
Feature class (feature type = polygon)
Feature class (feature type = arc)
Coverage (= feature class)
Feature type (arc)
Feature type (point)
Feature type (polygon)
Feature type (point)
Coverage (= feature
class)
Feature type (arc)
Feature type (point)
Locator (table)
Raster
Shapefile
Shapefile
Spatial file formats- Example- ArcCatalog view
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Type of storing of Vector Data :
ArcGIS from ESRI uses three different
implementations of the vector model to represent
feature data:
Shapefiles:.shp
Geodatabases: .mdb,gdb
and Coverages: dwg; dxf
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1. Vector data
1.1 Shapefiles
Shapefiles are stored in folders. A shapefile consists
of a set of files of vector data in the shapefile and a
dBASE®.dbf file containing the attributes of the
features. Each constituent file shares the shapefile
name.
Shapefiles are stored in three to five files (with
extensions .shp, .shx, .dbf, .sbx and .sbn).
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1.2 Geodatabases:
Some advantages of a geodatabase are that features in
geodatabases can have built-in behavior; geodatabase
features are completely stored in a single database;
and large geodatabase feature classes can be stored
seamlessly, not tiled.
In addition to generic features, such as points, lines, and
areas, you can create custom features such as
transformers, pipes, and parcels.
Storage of geodatabase features
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Geodatabase types:
Manages features and tables inside a database management system
Personal geodatabase
stores datasets in a Microsoft Access .mdb file
storage sizes between 250 and 500 MB
limited to 2GB
only supported on Windows
some higher level GIS functions can only be
performed if a geodatabase is created
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Geodatabase types:
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• File geodatabase
o stores datasets in a folder of files
o each dataset a file up to 1 TB in size
o can be used across platforms
o can be compressed and encrypted for read-only,
secure use
o ESRI’s recommended choice
• ArcSDE geodatabase
• stores datasets in a number of optional DBMSs:
• IBM DB2, IBM Informix , Microsoft SQL Server ,
Oracle, or PostgreSQL
• unlimited size and users
you can see that a_workspace contains two
coverages: a_coverage and b_coverage.
The a_coverage contains an arc feature class and a
tic feature class. This coverage has polygon topology,
so it contains a polygon feature class and a label
feature class as well. The dataset b_coverage is a
line coverage, so it just contains arc and tic feature
classes.
1.3 Coverages
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3.2 Data Types :Raster Data
Grids represent entities
Grids made of cells
Value applied to cell
In a Raster model, the world is represented as a
surface that is divided into a regular grid of cells.
Raster data
The x,y coordinates of at least one corner of the raster
are known, so it can be located in geographic space. 48
Raster models are useful for storing and analyzing data
that is continuous across an area. Each cell contains a
value that can represent membership in a class or category,
a measurement, or an interpreted value.
Raster data includes images and grids. Images, such as
an aerial photograph, a satellite image, or a scanned
map, are often used for generating GIS data.
The smaller the cell size for the raster layer, the
higher the resolution and the more detailed the map but
increases the total volume of data that must be stored.
Raster data
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Type of storing of Raster: Image Datasets
Supported image formats:
Windows bitmap images (BMP) [.bmp]
ERDAS [.lan and .gis]
ESRI Grid datasets
IMAGINE [.img]
Image catalogs
JPEG [.jpg]
MrSID [.sid]
National Image Transfer Format (NITF)
Sun rasterfiles [.rs, .ras and .sun]
Tag Image File Format (TIFF) [.tiff, .tif and .tff]
TIFF/LZW
GIF Graphic Interchange Format 50
Vector Data
Discrete features
Points: wells, Tel. poles
Lines: roads, rivers
Areas: landuse, veg. types, soil types
Uses points with x, y coordinates
Raster Data
Continuous features
Uses grids and cells with unique values
Rainfall, surface elevation, depths, soil erosion
Simple data structure (rows & columns)
File size depends on cell (pixel) resolution
Two Types of Data Models Used in GIS
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Good Representation of data.
Use small File Size.
Accurate map output.
Advantages (Vector)
Complex Data Structure.
Expensive Technology.
Analysis is Complex.
Disadvantages (Vector)
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Simple Data Structure.
Cheap Technology.
Analysis is Simple.
Same grid cell for several attributes.
Advantages (Raster)
Disadvantages (Raster) Large Data Volume.
Inefficient use of computer storage.
Difficult network analysis.
Less accurate or attractive maps.
Loss of information when using large cells.
Triangulated Irregular Networks (TIN):
TIN: is a series of triangles capturing the topography ..
x, y, z at nodes . Each triangle has a defined slope and
direction (aspect).
DEM : Digital Elevation Model data are stored and
processed as raster GRIDS
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4. People using GIS
Government
Tax maps; economic development; housing; law
enforcement; health
Science
Meteorology; biology; geology; geophysics;
education
Business
Retailing; marketing
Logistics
Transportation; disaster preparation
Environment
Landuse changes; water quality; pesticide
monitoring; soil erosion; air pollution
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GIS Technology
What is GIS
Components of GIS
Functions of GIS
Benefits of GIS
Real World Applications
Application of GIS in Transport
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• Input :Data Input - aerial photography, scanning, digitizing, GPS or global positioning system.
• Storage: hardcopy can be stored flat in map drawers. Digital data can be stored on CD, diskette or on your hard drive).
• Manipulation( digital geographic data can be
edited).
Functions of a GIS
Spatial data is the fuel of GIS.
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• Query & Analyze: see later
• Visualization : The ability to display your data,
your maps, and information about them.
Functions of a GIS
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Input Data: Scanner, Digitizer, GPS
Table Digitizing traces
objects on a paper map
Uses a digitizing
tablet
Heads-up Digitizing traces
objects on the screen
Scanned map, air
photo or satellite
image
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Global Positioning Systems
GPS is a revolutionary
navigation System
24 satellites orbiting
the earth
Provide location
within meters
anywhere on the
globe.
Now available in
many cars as an
option
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Earth Observation
LANDSAT
Landsat (TM)
RADARSAT
RadarSAT - Canadian
made satellite system
NOAA
NOAA National Oceanic and
Atmospheric Association
ERS ERS European
satellite
SPOT
SPOT Systeme Pour l’Observation de la
Terre
Geo Eye 61
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Query & Analysis: City maps in action
What is the fastest way to get
to a fire?
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Query & Analysis :
City maps in your neighborhood
What are the best
routes for your
school buses in
order to get
everyone home the
fastest?
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Query & Analysis : City maps...
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GIS - Query & Analysis
GIS software can answer
questions about our world:
What provinces border
Saskatchewan?
Spatial Questions:
What provinces have more
than 1.5 million people?
Attribute Questions:
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Query & Analysis
Planning the best
location for a new
ball park
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Query & Analysis
Study of drainage systems
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Query & Analysis
Evaluate areas most
susceptible to
landslide
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Query & Analysis
Nuclear waste site
planning
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Data View and Output
General map
Thematic map Unique values
Graduated color and symbol
Proportional Symbols
Pies and Charts
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Display and Symbolizing
Single Symbol
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Display and Symbolizing
Qualitative symbology
Unique values
Unique values but many fields
Matching to symbols in a style
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Display and Symbolizing
Quantitative symbology
Graduated Colors
Graduated Symbols
Proportional Symbols
Dot Density
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Display and Symbolizing
Charts (Multiple attributes)
Pie
Bar/column
Stacked
Multiple attributes
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Data Presenting
Graphs
Bar/column graphs
Line graphs
Pie graphs
3D graphs
Reports
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GIS Technology
What is GIS
Components of GIS
Functions of GIS
Benefits of GIS
Real World Applications
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Less Data Redundancy
More Timely Information
Easy Analysis of Information
Improved Management of Resources
Adaptable to Change
Expanded Opportunities for Analysis
Simulation and Modeling
Valuable Tool for Decision Management
Benefits of GIS The Importance of Using GIS
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Revision and updating easier
Search, analysis and representation easier
More value added products
Data can be shared and exchanged
Productivity more improved
Time and cost saved
Better decision making
Benefits of GIS The Importance of Using GIS
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GIS allows us to view, understand, and visualize data in
many ways that reveal relationships, patterns, and trends
in the form of maps, globes, reports, and charts.
A GIS helps you answer questions and solve problems
by looking at your data in a way that is quickly
understood and easily shared.
GIS give the accurate Data.
Better Predictions and Analysis.
Advantages of GIS
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Real World Applications
Public Utilities
Emergency 911
Health Care
Environmental
Environmental Map
Agriculture
Marketing
Real Estate
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“The application of GIS is limited only by the
imagination of those who use it.”
Jack Dangermond, President of ESRI
Real World Applications
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One day in life with GIS
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One day in life with GIS
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Public Utilities
Is it safe to
dig here?
A proposed excavation, identified by
address, is compared to pipelines in the area
using Geotechnology.
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Emergency 911
What is the
fastest route to
the Hospital?
Geotechnology can choose the
fastest route to a hospital. The
GIS can take into account
traffic and other impediments. 85
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Health Care
What
Communities are
at risk from
Disease?
Geotechnology identifies
communities at risk of River
Blindness and helps determine
the impact of treatment.
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Environmental
What are the
effects of
Global
Warming?
Land cover and temperature relationships are
made clear when the data are seen at once
using Geotechnology.
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Agriculture
How can I improve
food production?
Geotechnology is used in
making crop management
decisions to maximize yields
and minimize fertilizer input.
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Tsunami Relief
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Hurricane Tracking and Response
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Marketing
How can I
optimize my
Marketing
Campaign?
Geotechnology can query a database and
identify only those areas with the highest
household income within a specified distance
of a store.
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Real Estate
Where is my
Dream Home?
With Geotechnology, an agent can
show a map of a neighborhood and a
picture or video of the actual
properties.
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GIS Applications for Transportation
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Evaluate traffic flow
Transportation
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Transportation
Provide
maps for a
corridor
study
Graphic: ESRI Map Book 97
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Transportation
GIS can be
web
enabled to
display
traffic
counts
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Transportation
GIS can be web
enabled
interactively
display accident
locations and
driving alerts.
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Transportation
GIS assist with
project management
and budgeting
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Determine
the drive-times
Transportation
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The seven parts of every Research Project
Objective, explains the purpose of the research and why it is
important Usually includes Hypotheses: possible explanations which you will test
Literature Review, identifies the key pieces of existing research relevant to the project and the hypotheses
Data Sources, identifies and explains the data used.
Analysis and Methodology, explains the methodology applied to the data.
Results, describes the main research findings, whether or not the hypotheses were upheld, and any potential problems or shortcomings
Conclusion, discusses the implications of your results relative to your initial project objective.
References, provide standard format citations for all resources used in the project.
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Thank You
