1. Lecture 4 Data

2. Why GIS? Ask questions Solve a problem Support a decision Make Maps Involve others, share data, procedures, ideas

3. What is a GIS? GISs are simultaneously the telescope, the microscope, the computer, and the Xerox machine of regional analysis and synthesis of spatial data. (Ron Abler, 1988)

4. Definition 1: A GIS is a toolbox "a powerful set of tools for storing and retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes" (Burrough, 1986, p. 6). "automated systems for the capture, storage, retrieval, analysis, and display of spatial data." (Clarke, 1995, p. 13).

5. Definition 2: A GIS is an information system "An information system that is designed to work with data referenced by spatial or geographic coordinates. In other words, a GIS is both a database system with specific capabilities for spatially-referenced data, as well as a set of operations for working with the data" (Star and Estes, 1990, p. 2).

6. Definition 3: GIS is an approach to science Geographic Information Science is research both on and with GIS. "the generic issues that surround the use of GIS technology, impede its successful implementation, or emerge from an understanding of its potential capabilities." (Goodchild, 1992)

7. Definition 4: GIS plays a role in society Nick Chrisman (1999) “organized activity by which people measure and represent geographic phenomena, and then transform these representations into other forms while interacting with social structures.”

8. Components of a GIS Hardware Software Procedures People with skills to complete tasks Data

9. Hardware Computer, CPU, memory, and monitor Modem and internet connection Data collection devices, GPS, handheld data Scanner or digitizing table Plotter and printer Web Server

10. Software GIS software – range of functions Software extensions – add functions Data viewers – least functionality Single purpose software – make parcel maps Software for the web – ATM, House locators Non-GIS software - database, statistics, image processing

11. Procedures Data input – paper maps, GPS, images Data management - edit and quality Query - Asking map questions Analysis - Spatial, tabular and statistical analysis  Map overlay  Distance calculations Data output - Map making, on screen, paper, internet

12. People with spatial knowledge Data entry Data quality Analyst Developer / Programmer Database manager Web developer Project manager GIS manager www.gjc.orgwww.gjc.org - GIS jobs listing

13. Data types  Maps and Layers  Vector  Raster  TIN  3D  Text  Metadata

14. Data storage formats Maps and layers  Mxd  lyr Vector  Geodatabase, shapefile, coverage  DXF, DWG DGN Raster  GRID, sid, img, gif, jpeg Tables  Geodatabase, dbf, 3D  TIN format

15. Vector data Point - x, y Line - list of x, y coordinates Polygon - list of lines that form a closed area Points 4753456 623412 4753436 623424 4753462 623478 4753432 623482 4753405 623429 4753401 623508 4753462 623555 4753398 623634 LinesPolygons

16. Vector layers

17. Feature class Group of points, lines, or polygons Has a theme-rivers, streets, cities, lakes, states… Makes a layer Point feature class Line feature class Polygon feature class

18. Shapefile Three files,.shp, (.dbf,.shx) Files contain either points, lines, or polygons

19. Layer files File for one layer, stores its symbology.lyr extension, streets.lyr Add to any map or share with friends No data  Pointer to data  Symbols

20. Geodatabase One file - Access format.mdb file Point, line, & polygon feature classes Tables too

21. What is a database Storage format Container for tables of data Allows queries The sales table contains five tables

22. Table structure Fields Rows Cells

23. A feature class table Has a geometry field You can’t see the actual values, too big

24. Field menu Sort

25. Options menu

26. Select By Attributes

27. Build a SQL expression Field, Operator, Value to search for

28. Records get selected Pop90_SQMI < 30

29. Features get selected too Pop90_SQMI < 30

30. Make table steps Get or make a database Make a table Add fields Add records Add values

31. Make a personal geodatabase

32. A.mdb file is Microsoft Access format

33. Make a new table in the database

34. Name it and default configuration

35. Add fields, type in name and type

36. Data Types and Length

37. Drag the table to ArcMap for editing

38. Add Editor toolbar, Start editing

39. Empty table to start, start typing

40. Type a value into a cell

41. Type in all values

42. Stop editing, save edits

43. Turn off Editor toolbar

44. Make a Geodatabase exercise Make an access database Convert a shapefile Build relationships with other tables Add fields Calculate fields Join fields