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Lecture 04 - 07:
Introduction to GIS
Geographic Information System (GIS)
By: Md. ESRAZ-Ul-ZannatAssistant ProfessorDepartment of Urban and Regional PlanningKhulna University of Engineering and Technology (KUET), Khulna-9203, Bangladesh
Date: 18 January 2015
2
Acknowledgement
These slides are aggregations for better understanding of
the topic mentioned in the previous slide . I
acknowledge the contribution of all the authors and
photographers from where I tried to accumulate the info
and used for better presentation.
3
Topics to be Covered by this Presentation
ArcGIS views Data Management – Database View
Analysis – Model View
Visualization – Map View
GIScience, GISystems, GIStudies & GIServices
Who needs Advantage GIS?
Why is GIS Important?
Why is GIS so HOT?
GIS Challenges
Why spatial is special?
GIS is not......
The future of GIS
Geographical information service
Ways of Collecting GIS Data
4
Topics to be Covered by this Presentation
Possible Sources of GIS data
GIS Field of Applications
Major GIS Applications in Water Sector
Importance of Layers in GIS
How Do We Create Geographic Information?
Major Disciplines & Technologies
Ideal GIS
● Data Management –Database View
● Analysis –Model View
● Visualization – Map View
What is GIS?
● Data Management -
1. Manages various kinds of GIS data including vector,
raster, images, tables, other data files
2. Data models and architectures
3. Conversion between formats
4. Import/export utilities
5. Interacts with RDBMS (SQL Server, Oracle, etc…)
What is GIS?
● Analysis
1. Spatially aware data
2. Attribute and spatial query
3. Proximity and Overlay
4. Advanced geoprocessing techniques
5. Decision support
6. Flexible, customization
7. Programming, scripting (to perform analysis)
What is GIS?
● Visualization
1. Maps! Maps! Maps!
2. If a picture is worth a 1000 words…
3. Professional cartographic tool
4. Charts, graphs, tables, etc…
5. Various coordinate systems
6. 2D and 3D
7. Web, desktop, handheld, etc…
What is GIS?
● GIS uses maps to spatially analyze and search for patternsin the data that would otherwise not be found. (Content)
● GIS stores, manipulates, and displays data files andrelationships in a information system using standardcomputing practices. (IT)
● With advances in technology, GIS users must now deal withboth aspects!
“G” vs. “IS”
“G” = Geographic
● Denotes the concept of spatial location on Earth’s surface
● Importance of relative location (not just where you are butwhere you are in relation to everything else)
● Theories and techniques in Geography form the basis of GIS
The “G”?
“I” = Information
● Substance (knowledge) about location
● Factual and interpretative
● Tables + Maps + Analysis
● Transformation of table information into spatial context foranalysis
● Technology and computer systems
The “I”?
● Yes, it is used quite often.
● Commonly used as a replacement for or broadening of theterm “GIS data”
● But…
What about just “GI”?
● Science
● Systems
● Studies
● Services
What About the “S” in GIS?
System, science, study and service
Geographical information system
Emphasising infrastructure
Geographical information science
Emphasising principle and theory
Geographical information study
Emphasising data and data mining
Geographical information service
Emphasising socio-economic service
GIScience, GISystems, GIStudies & GIServices
GISystems
GIStudiesGIScience
GIServices
GIScience, GISystems and GIStudies
● GIScience – fundamental scientific issues arising from theuse of GISystems (concepts, techniques)
● GISystems – implement the storehouse of GIScienceknowledge (tools, techniques)
● GIStudies – how systems and science are embedded in asocietal context
● GIServices – basically the products/outcomes of the abovethree
● Understanding GIS requires consideration of science,systems and studies
● GIS provides a framework to manage the world
● The real value of GIS is its problem solving capability
● The future of GIS and GISci is bright
GIScience, GISystems and GIStudies
● Geographic + GIS = “Geospatial”
● Move in recent years to better define the industry and tofocus on data (business) over geographic principles(academic)
● Geospatial includes all subcomponents of GIS embedded inother areas (remote sensing, GPS etc.)
Geospatial?
● County Governments
● City Governments
● Local Utilities
● Police Departments
● Fire Departments
● School Districts
● Non-Profit Organizations and many more
● Anyone who is seeking a way to organize data and get answers.
Who needs Advantage GIS?
● GIS technology is to geographical analysis what themicroscope, the telescope, and computers have been toother sciences.
● It integrates spatial information within a singlesystem.
● It allows us to manipulate and display geographicalknowledge in new and exciting ways.
Why is GIS Important?
● GIS gives a “high tech” feel to geographic information.
●Maps are fascinating and so are maps in computers.
● There is increasing interest in geography andgeographic education.
● GIS is an important tool in understanding and managingthe environment .
Why is GIS so HOT?
● It is the most advanced electronic tool for examining spatialinformation in an organized manner.
● Provides powerful tools for
- data process, analysis, and visualization
- data management and retrieval
● One of the fastest growing high-tech career fields
Why GIS?
- wider availability of GIS through the internet, as well asorganization-wide local area networks
- Reductions in the price of GIS hardware and software- Greater awareness of why decision-making has a
geographic dimension- Greater ease of user interaction, using standard
windowing environments- Better technology to support applications, specifically in
terms of visualization, Data management and analysis, andlinkage to other software
- The proliferation of geographically referenced digital data,such as GPS
- Availability of packaged applications-The accumulatedexperience of applications that work
Why GIS?
Why GIS?
GIS Challenges
Spatial information is important because “almost everything that happens,
happens somewhere. Knowing where something happens could be critically
important”(Longley et al. 2011). This sentence is important fore disaster
risk management to know which areas could be vulnerable to plan
prevention and response. For instance, One of the first use of maps to
do an spatial analysis was done by John Snow during cholera outbreak in
London (year 1854). John Snow used a map of London streets to study
cholera individual cases distribution. The map point to the source of the
decease, a water pump (see Fig. 1). “A picture tells a 1000 words”
Fig. 1. A variant of the original map drawn by Dr. John Snow (1813-1858), a British physician who is one of the founders of medical epidemiology, showing cases of cholera in the London epidemics of 1854, clustered around the locations of water pumps.
Why spatial is special?
*it is multidimensional, at least two coordinates must be specified to define a location
*it is voluminous, can easily reach a terabyte in size*It must be projected onto a flat surface
*it requires many spatial methods for its analysis
*it can be time-consuming to integrate and analyze the many varied types of geographic information
*Although much geographic information is static, the process of updating is complex, and expensive
*Display of geographic information in the form of a map requires the retrieval of large amounts of data
Why spatial is special?
Reasons why geographic information is special!
.....simply a computer system for making maps, although it can
create maps at different scales, in different projections, and
with different colors. A GIS is an analytical tool. The major
advantage of a GIS is that it allows you to identify the spatial
relationship between map features. A GIS does not store a
map in any conventional sense; nor does it store a particular
image or view of a geographic area. Instead, a GIS stores the
data from which you can draw a desired view to suit a
particular purpose.
GIS is not......
Technology diffusion
People oriented applications
Interactive and real-time applications
Cleverer and more comprehensive
To use GIS, or not to use?
The future of GIS
Geographical information service
Image View
Map View
3D View
Street View
Get Direction
Everything has a location
Everyone is a Provider
Everyone is connected
And many more such as
weather station observations
water meter readings,
sampler analysis results,
daily sale amounts census
results ……..
Ways of Collecting GIS Data
● Published Paper Maps
● Aerial Photographs - Photogrammetric Mapping
● Satellite Imageries - LandSat, Spot, RADAR SAT etc.
● Global Positioning System (GPS) Survey
● Civil Surveying - Total Station, Plane Table survey
● Geodetic Survey – Bench Mark Datum Level
● Digital data from other organization
Possible Sources of GIS data
● Agriculture
● Archaeology
● Business
● Environment
● Geology
● Health
● Hydrology
● Land Information System
● Military
● Natural Hazard Management
● Natural Resource Management
● Urban Planning
● Many more ……
http://www.gisdevelopment.net/application/index.htm
GIS Field of Applications
Flood Depth
Inundation
Mapping
& Depth-Duration
Analysis
Analysis of
Morphological
Changes of
River Plan form
Topographic
Survey & Mapping
Digital Elevation
Model, Contour
Preparation
Interactive Geo-referenced Database,
Analyses, Presentation and Mapping
Major GIS
Applications
Water and
EnvironmentCrop Damage
Assessment
due to
Inundation
Based on
Satellite
Imageries
Environmental Impact
Assessment &
Salinity Mapping
Application
Development
Elevation in mPWD
Area Elevation Curve
Long Profile of River
Time Series Graphs
Real Time Flood Mapping based on Model Data
Cut / Fill and Conveyance Calculation
Landuse Changes over the period
DEM comparison
Cross Section Profile &
Comparison with previous Data
Interpretation of Satellite Imagery
Topographic Survey and Mapping
Digital Elevation Model (DEM), Contour & Bathymetry
Flood Inundation & Salinity Mapping
Major GIS Applications in Water Sector
Core of GIS = “Layers”
● Geographic data = Representation of reality
● Reality is complex.
● GIS utilizes a layer approach
● Each layer only includes information about one type ofphenomenon.
● Data layers must be aligned with one another
Importance of Layers in GIS
Aerial
Photography
Land
Surveying
GPSWhat Where
Geographic
Information
Fields
Samples
Population
Census
Administrative
Records
How Do We Create Geographic Information?
● GIS is a convergence of technological fields andtraditional disciplines.
● GIS has been called an “Enabling Technology”.
● GIS is associated with other Major FollowingDisciplines:
● Geography
● Cartography
● Remote Sensing
● Photogrammetry
● Statistics
● Computer Science
Major Disciplines & Technologies
● Broadly concerned with understanding the world andman’s place in it.
● Long tradition in spatial analysis.
● Provides techniques for conducting spatial analysis.
Geography
● Computer cartography provides methods for digitalrepresentation.
● It is concerned with the display of SpatialInformation.
● It provides long tradition in the design of maps whichis an important form of output from GIS.
Cartography
● Remote Sensing includes techniques for dataacquisition and processing anywhere on the globe at lowcost.
● Images from space and the air are major source ofgeographical data.
● Interpreted data from a remote sensing system can bemerged with other data layers in a GIS
Remote Sensing
● Photogrammetry is the source of most data used forinput to GIS.
● In Photogrammetry we use aerial photography formaking measurements.
Photogrammetry
● Statistics is important in understanding issues of errorand uncertainty in GIS data.
●Many models are built using GIS are statistical innature.
●Many statistical techniques are used for analysis.
Statistics
● CAD provides software, techniques for data input,display and visualization.
● Advances in computer graphics provide hardware,software for handling and displaying graphic objects.
● DBMS contribute procedures for system design andhandling large volume of data.
Computer Science
● Data Processing System
● Data Analysis Subsystem
● Information User Subsystem
GIS as a set of Integrated Subsystem
● Data Acquisition : from maps, images or field surveys.
● Data Input : data must be input from source materialto the digital database.
● Data Storage : how often is it used, how should it beupdated, is it confidential?
Data Processing Subsystem
● Retrieval and Analysis : may be simple responses toqueries, or complex statistical analysis of large sets ofdata.
● Information Output : how to display the results? Asmaps or tables? Or will the information be fed intosome other digital system ?
Data Analysis Subsystem
● Users may be researchers, planners, managers
● It provides interaction between GIS group and usersto plan analytical procedures and data structures.
Information User Subsystem
Data from Maps
Tabular data
Field data
Data from other
digital database
Remote sensing
Global positioning
system
Reports
Maps
Photographic
products
Statistics
To other digital
database
Input to Models
Geographic Information System
Database Management
Ideal GIS
Power of GIS - Integration
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Topics Covered by this Presentation
ArcGIS views Data Management – Database View
Analysis – Model View
Visualization – Map View
GIScience, GISystems, GIStudies & GIServices
Who needs Advantage GIS?
Why is GIS Important?
Why is GIS so HOT?
GIS Challenges
Why spatial is special?
GIS is not......
The future of GIS
Geographical information service
Ways of Collecting GIS Data
60
Topics Covered by this Presentation
Possible Sources of GIS data
GIS Field of Applications
Major GIS Applications in Water Sector
Importance of Layers in GIS
How Do We Create Geographic Information?
Major Disciplines & Technologies
Ideal GIS
What We Learnt
Understanding of GIS, its application, its fundamentals
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What Next?
Lecture 08 - 14:Fundamentals of GIS