1. CS 128/ES 228 - Lecture 7a1 Digital Map Sources II

2. CS 128/ES 228 - Lecture 7a2 The first rule of building a GIS Try to use somebody else’s data before you even think of generating your own

3. CS 128/ES 228 - Lecture 7a3 4. Vector data formats

4. CS 128/ES 228 - Lecture 7a4 Digital line graphs (DLGs)  Scales 1:24,000 1:100,000 1:2x10 6  Full topological data structure (nodes, lines, areas + adjacency information)  Layers: 9 feature classes, street & address information, elevations  Projection: UTM (large & medium scale), Albers Conical Equal Area (small scale)

5. CS 128/ES 228 - Lecture 7a5 DLG Topology  Lines = ordered sets of points with a node at each end. They can’t cross themselves or other lines  Nodes = endpoints of lines (points are degenerate lines that start and end at the same node!)  Areas = continuous regions bounded by lines. Not true polygons – areas are constructed from bounding lines and an area identifier

6. CS 128/ES 228 - Lecture 7a6 Area hybrid topology  Network & area info in same file  All closed line circuits define areas – but not all areas have cartographic identities  Hydrology ex: lakes and streams

7. CS 128/ES 228 - Lecture 7a7 Tributaries are single lines Two Mile Creek near campus

8. CS 128/ES 228 - Lecture 7a8 Rivers are made of 2 lines Allegheny River near campus

9. CS 128/ES 228 - Lecture 7a9 Major feature classes

10. CS 128/ES 228 - Lecture 7a10 Major attribute codes

11. CS 128/ES 228 - Lecture 7a11 Minor attribute codes

12. CS 128/ES 228 - Lecture 7a12 Olean DLG: all layers

13. CS 128/ES 228 - Lecture 7a13 Olean DLG: roads (4 layers)

14. CS 128/ES 228 - Lecture 7a14 Olean DLG: add water features

15. CS 128/ES 228 - Lecture 7a15 Olean DLG: add railroads

16. CS 128/ES 228 - Lecture 7a16 Olean DLG: add contours

17. CS 128/ES 228 - Lecture 7a17 5. TIGER maps U. S. Census Bureau’s DLG format Include county, census tract, & census block De facto standard/source for most commercial geocoding and trip planning software Topologically Integrated Geographic Encoding & Referencing system

18. CS 128/ES 228 - Lecture 7a18 The TIGER map browser

19. CS 128/ES 228 - Lecture 7a19 Center on a familiar point…

20. CS 128/ES 228 - Lecture 7a20 TIGER for Allegany NY

21. CS 128/ES 228 - Lecture 7a21 TIGER files in ArcMap

22. CS 128/ES 228 - Lecture 7a22 Census IDs

23. CS 128/ES 228 - Lecture 7a23 Census Bureau databases American Factfinder Reports in table or map form Joins or relates?

24. CS 128/ES 228 - Lecture 7a24 NYS Income, by county

25. CS 128/ES 228 - Lecture 7a25 Resolution to the census tract

26. CS 128/ES 228 - Lecture 7a26 Local demographic stats

27. CS 128/ES 228 - Lecture 7a27 Local housing costs

28. CS 128/ES 228 - Lecture 7a28 Thematic Census maps

29. CS 128/ES 228 - Lecture 7a29 Themes may be reclassified

30. CS 128/ES 228 - Lecture 7a30 Equal frequency classification

31. CS 128/ES 228 - Lecture 7a31 Summary: digital data sources  Digital raster graphs (DRGs)  Digital line graphs (DLGs)  TIGER files