1. Lecture 3 How does GIS work

2. How does GIS work? Maps are stored in computers Databases and Tables Geometry Attributes

3. How does GIS work? Categories of reality are divided into layers Countries, States, Cities Parcels of land ownership Roads, Rivers, Lakes, Buildings ZIP codes

4. How does GIS work? Layers are made up of points, lines, or polygons Cities – points Roads – lines Counties – polygons

5. Drawing maps Points, lines, polygons, and text Main Street Home Work Construction Mall

6. Change street layer color and thickness Main Street Home Work Construction Mall

7. Turn Streets layer off Main Street Home Work Construction Mall

8. World country layer - polygons

9. Amelia Earhart’s last flight - lines

10. Cities (fuel stops) - points

11. Levels of geography Country State County City DEMO http://www.marshallco.org/www/maps/images/50seregexpl.jpg

12. Levels of geography Block group http://www2.lib.udel.edu/subj/maps/internet/dedo/nnccinc.htm

13. Levels of geography ZIP code http://cssr.berkeley.edu/cwscmsreports/maps/showEntriesCountymap.asp?page=Ora

14. Levels of geography Parcel Buildings Houses

15. GIS links attribute and spatial data  Each layer has a database table  Each map feature has one record in the table  The table has attributes about the features

16. One to one: layer and table One to one: map feature and record

17. Is your data spatial? >80 percent of all data has location “What’s your ZIP code”

23. My customer database

24. Here is my store

25. ArcMap puts customers on the map

26. Before GIS Just Pens and Paper http://www.census.gov/pubinfo/www/photos/img/lowres/Hist08l.jpg

27. GIS Power Just a database Tools Analysis GIS Science and Geography Geo Statistics Aids in decision making Remember “Maps Communicate”

28. Which 8% of 7000 stores to close? http://money.cnn.com/news/specials/storysupplement/starbucks_closings/CA.html

29. Where can we add new stores/Delis?

31. 5 steps to GIS analysis

32. Frame the question Get the data Choose analysis method Process the data Look at the results

33. Frame the question Where can we put a garbage dump?

34. Frame the question Where can we put a garbage dump? Not on bad soil Out of the city Not in a park Not in a protected area like a forest More?

35. Get the data SOILS PARKS URBAN FOREST Color in the unacceptable areas Can’t locate in dark areas

36. Choose analysis method SOILS PARKS URBAN FOREST OVERLAY the layers on top of each other

37. Process the data SOILS PARKS URBAN Solution map FOREST Color in the unacceptable areas

38. Look at the results

39. Check out other similar projects http://www.ruralgis.org/conference/2004proceedings/thurs/session4/thurs_4_1_00.pdf

40. Map Overlay But what about the protected rats? SOILS PARKS URBAN Solution map FOREST Rats

41. Before GIS - Paper Computers speed the process Databases hold more information than paper Why GIS?  Faster  Cheaper  Easier  More http://www.census.gov/pubinfo/www/photos/img/lowres/Hist08l.jpg