Introduction to GIS

1. Introduction to GIS Ghassan Mikati, Ph.D GIS Expert

2. Definition of GIS A computer system which can hold and use data describing places on the earth's surface.

3. What is GIS? GIS is: • A mapping software – such as Electronic Atlas: • It displays pictures of geographic areas on the computer • It provides information about these areas • It provides ability to alter graphics • And even more than that, it has the ability: • To create graphics using information database • To import external information & databases • To use tabular information to create charts & graphs • And to analyze information statistically

4. Computer Hardware & Software Organizational Structure & People Components of GIS Database

5. Components of GIS • Hardware:the computer on which GIS operates • Software:which provides the functions and tools needed to store, analyze, and display geographic information. • Data:geographic data & related tabular data • People:GIS users who range from specialists to simple users • Methods:a designed plan and business rules

6. Raster vs. Vector GIS works with two models: • Vector: information is encoded and stored as a collection of x,y coordinates • Raster: comprises a collection of grid cells

7. GIS Layers • GIS stores information about the world as a collection of thematic layers that can be linked together by geography

8. Roads Park River On a Map… • Every object is called Map Feature…

9. Geographic Features Geographic features are represented by two types of data. Street Name Address range on left Address range on right Length to travel Directions to travel SPATIAL DATA ATTRIBUTE DATA

10. Sites as points Roads as lines Park & River as areas On a Map… • Map features are represented as points, lines or areas…

11. Each column stores a different attribute Each row relates to a single feature Related Information… • GIS stores all descriptive information about features as attributes in a GIS database.

12. The Map/Table link • Any change in the attribute table is reflected on the map.

13. The Map/Table link

14. Roads Parks Buildings River Features & Attributes • Sets of features and attributes together are called themes:

15. Roads Buildings Parks River GIS Database • All themes together make the GIS database

16. City as point Building as polygon Roads as polygon Roads as lines On a Map… • Map scale controls the size of features and shapes used to represent them, i.e. when map scale increases, so does the size of the map feature.

17. Getting Answers to Questions With GIS we can: • Get information about features • Find features based on their attributes • Analyze features locations

18. LOCATION: What is at...? • Here we are seeking to find out what exists at a particular location. • A location can be described in many different ways using, for example, place name, or latitude and longitude coordinates

19. LOCATION: What is at...? Identifier: 565-88-221 Area: 108,900,245 Owner: John Morris Address: 3233 Texas St. Zoned land use: Industrial Assessment: $950,000

20. LOCATION: What is at...? • Getting other types of information about a feature

21. CONDITION: Where is it? Instead of identifying what exists at a given location, you want to find a location where certain conditions are satisfied. For example, you wish to find a house assessed at less than $200,000 with 4 bedrooms and made of wood.

22. Result Map Within a certain price 4 Bedrooms More than a certain area CONDITION: Where is it? • Find features based on attributes they share

23. TRENDS: What has changed since...? This seeks to discover the differences between an area as the result of the passing of time.

24. TRENDS: What has changed since...? City in 1990 City in 1950

25. PATTERNS: What spatial patterns exist? This seeks to discover what types of patterns may exist in the newly created data file that were not visible before. For example you may wish to know where motor vehicle accidents occur and at what times.

26. PATTERNS: What spatial patterns exist? What kinds of patterns exist for motor vehicle accidents? Where do they occur and at what times?

27. Spatial Query: What spatial link exist? • GIS locates features with regards to their location to each other: • Features adjacent to… • Features within a certain distance • Features within a certain area • Etc…

28. Apartments for sale within 0.5 km Apartments for sale Schools High School Spatial Query: What spatial link exist? • Looking for an apartment within 0.5 km from high school

29. vehicle routing and scheduling location analysis, site selection development of evacuation plans Major Areas of Practical Application of GIS Technology Street Network-Based

30. Major Areas of Practical Application of GIS Technology Facilities Management • locating underground pipes, cables • balancing loads in electrical networks • planning facility maintenance • tracking energy use

31. Major Areas of Practical Application of GIS Technology Land Parcel-Based • zoning, subdivision plan review • land acquisition • environmental impact statements • water quality management

32. Major Areas of Practical Application of GIS Technology Natural Resource-Based • forest management • habitat, migration routes management • wild and scenic rivers preservation • recreation resources planning • wetland preservation • agricultural lands management • groundwater modeling and contamination tracking