1. Introduction to Geographical Information Science RSG620
Week 1, Lecture 2
Feb 17, 2016
Department of RS and GISc
Institute of Space Technology, Karachi
Introduction to Geographical Information Science RSG620

2. Introduction to GIS What is GIS? G ? Geographical I ? Information
S? System
Science
Studies

3. S in GIS? S as in System S as in Science S as in Studies
Technology (for acquiring and managing GIS data)
S as in Science
Concept behind the technology. Theoretical foundation on which GI Systems are based
S as in Studies
Societal context (social, legal, and ethical issue of privacy and confidentiality related to GIS application)

4. Why Geography is important?
Why are we more interested in spatial data today than 100 years ago?
Reference: Bolastad, 2008

5. How an object on Earth can be defined?

7. Location Information: Where is it? Attribute Information: What is it?
There are two ways of explaining any element/object on the Earth
…….
Location Information: Where is it?
Attribute Information: What is it?
GIS can tell us Where and What
Geospatial data tells you where it is and attribute data tells you what it is. Metadata describes both geospatial and attribute data

8. Why GIS is Important? What is Where? : Where is what? Or
Query information to find location Or
Where is what?
Obtain information from a location
Impact of spatial information on our lives?
Applied geography, in the form of maps and spatial information, has served mankind in many applied fields like navigation, discovery, planning, etc. for at least the past 3,000 years
What is Where?
At which pole polar bear lives?
Where you may find rain forest?
Where is what?
At North Pole what dominant land animal is found?
At tropical region what type of forests are found?

9. GIS is about Geospatial Information
Geospatial Information: Information about places on earth
Not only Where and What but time is also important
What is Where, When?

10. Simpler Definitions
A GIS helps us gather and use spatial data (Bolstad)
A computer system which can hold and use data describing places on the earth's surface.

11. GIS...
A GIS is not simply a computer system for making pretty maps. More importantly a GIS...
... is an analysis tool
... links spatial data with geographic information about a particular feature on a map
... can use the stored attributes to compute new information about map features
Source of this slide: Tim Haithcoat

12. A more Comprehensive Definition
A GIS is a computer-based system to aid in the collection, maintenance, storage, analysis, output, and distribution of spatial data and information

13. Some other popular definitions of GIS
A powerful set of tools for collecting, storing, retrieving, transforming and displaying spatial data from the real world. (Burrough, 1986)
Any manual or computer based set of procedures used to store and manipulate geographically referenced data. (Aronoff 1989)

14. Some other popular definitions of GIS
A decision support system involving the integration of spatially referenced data in a problem solving environment. (Cowen 1988)
Systems that know how to deal with stuff in space. (Herrington 1998)

15. Conventional Ways to Store Data
DATABASES
A Database comprises of tables having fields with specific data structure.
The tables are linked with each other through various common fields.
Data

16. Conventional Ways to Store Data
MAPS
Map can be defined as “A Facility for displaying interpretation of geographic information on a flat surface.”
Location information describes the position of a particular geographic feature on earth's surface & provides the basis for representing spatial relationships between these features.
Map

17. Visual Interpretation Visual Interpretation
Databases Vs Maps
Very good
Searching
Bad
Searching
What? if link
together
Bad
Visual Interpretation
Very Good
Visual Interpretation

18. Basic GIS Functions

19. Basic GIS Functions
Capture Collecting data using different data structures and technologies – GPS, RS, Digitizing, etc.
Store Data stored in the form of databases, spatial files, drawings, images, etc.
Query A GIS must provide utilities for finding specific features based on their location or attribute values
Analyze A GIS must have the ability to answer questions
regarding the interaction of spatial relationships between multiple datasets
Display There must be tools for visualizing the spatial information in the form of maps
Output Results of display should be able to be output in a variety of formats

20. GIS Functions
Data Capturing

21. GIS Functions
Tables
Storing Data

22. GIS Functions Spatial Query Query: Select Florida county Taylor on map
spatial queries (how many utility stores within 10 minutes from major highways?, How many emergency services located within a community?)
Query: Florida counties with a population greater than 300,000

23. GIS Functions Spatial Analysis
Create a new area within a user-defined distance of an existing entity.

24. Remember!! Queries manipulate the database
Analysis transforms data into information

25. GIS Functions
Display

26. GIS Functions
Output

27. GIS Functions Output Soft Copy Hard Copy
Electronic map (visual digital map + multimedia)
Digital Atlas
Digital Layouts
Web Based Maps (Interactive Web Mapping)
Soft Copy
Maps (Topographic, Statistical, 3D, Contour etc)
Atlases
Reports (Write-ups etc)
Charts, Graphs
Hard Copy

28. GIS Key Components GIS hardware GIS software
GIS data (maps, images, database, etc.)
People
Methods
GIS require trained people to use them.
Picture reference:

29. GIS Components
Hardware
Hardware is the computer system on which software operates

30. GIS Components
Hardware
Reference: Bolstad

31. GIS Components
Software
Many public domain and commercially available software packages in the market
ESRI (Environmental Systems Research Institute) line of products a good example (including ArcGIS)

32. GIS Components Key components to GIS software:
An easy-to-use graphical user interface (GUI)
Tools for entering and manipulating geographic information
Tools that support geographic query, analysis and visualization
A database management system (DBMS)

33. GIS Components Map + Database
GIS Data
Map + Database
Digital maps (virtual representation of world)
Map = Spatial representation of features
Database = Feature attributes
Data Sources
Available through various sources like profit and non- profit organizations, academic institutions, government agencies

34. GIS Components GIS Data Flood Zones Wetlands Landcover Electric Lines
Gas Pipe Lines
Soils
Land Ownership
Transportation
Surface Waters
Boundaries
Geodetic Control
Elevation
Satellite Imagery
GIS Combines Data from Many Sources

35. GIS Components GIS personnel may include
People
GIS personnel may include
GIS technologist to design and maintain the system
General programmers
GIS developers
GIS Users
GIS Managers
Data providers
GIS specialist/analyst
General users and Public users

36. GIS Components Analysis to be performed on data
Methods
Analysis to be performed on data
To answer the question needs to be resolved
How to
Retrieve
Input into the system
Stored
Managed
Transformed
Analyzed
Presented as output

37. Other GIS Components Supporting institution Protocol for use
Although new users often focus on GIS hardware and software components, we must recognize that GIS exists in an institutional context. Effective use of GIS requires an organization to support various GIS activities. Most GIS also require trained people to use them, and a set of protocols guiding how the GIS will be used. The institutional context determines what spatial data are important, how these data will be collected and used, and ensures that the results of GIS analyses are properly interpreted and applied. GIS share a common characteristic of many powerful technologies. If not properly used, the technology may lead to a significant waste of resources, and may do more harm than good. The proper institutional resources are required for GIS to provide all its potential benefits.

38. Some Advantages of GIS
Automation of procedures involving geographic data (map making, calculation of area, slope, etc., and planning and management activities)
Integration of data from different independent domains
Visual Interpretation of spatial data depending on various criteria
Perform Spatial Queries and complex Spatial Modeling (what if scenarios)
More

39. GIS Benefits
Geo-spatial data are better maintained in a standard format
Revision and updating are easier
Easier to search, analyze and represent
More value added as well as thematic product
Geo-spatial data can be shared and exchanged easily
Time and money are saved
Better decisions in short span of time

40. Thank You