Introduction to Geographical Information Science RSG620

1. Introduction to Geographical Information ScienceRSG620 Week 1, Lecture 2 Feb 17, 2016 Department of RS and GISc Institute of Space Technology, Karachi

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

3. S in GIS? • S as in System • 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 GIS can tell us Where and What

8. Why GIS is Important? • What is Where? : • 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

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

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

13. 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) Some other popular definitions of GIS

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

18. Basic GIS Functions

19. 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 Basic GIS Functions

20. GIS Functions Data Capturing

21. Tables GIS Functions Storing Data

22. GIS Functions Spatial Query • Query: Select Florida county Taylor on map • Query: Florida counties with a population greater than 300,000

23. GIS Functions Spatial Analysis

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

25. GIS Functions Display

26. GIS Functions Output

27. GIS Functions Output • 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 Picture reference: http://www.mapsofindia.com/images/gis-components.jpg

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

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 Software • 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 GIS Data • 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 Map + Database

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 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 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

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