1. On Some Fundamental Geographical Concepts 176B Lecture 3

2. Nystuen, J. D. (1963) “Identification of some fundamental spatial concepts” Search for a common geographical terminology to eliminate redundancy Basics: Distance, pattern, relative position, site and accessibility Advantages of abstract models and assumptions, e.g. isotropic surface

3. The mosque floor

5. Geographic primitives G = g (x, y, z, s, A, t) [x, y, z] = f(  d  Geography also highly dependent upon model

6. UCSB Lat: 34.4087 Lon: -119.8447

7. Projection, datum etc. for a 7.5 min quad

8. GIS basic geometric functions A GIS package must be able to move between –map projections –coordinate systems –datums –Ellipsoids A GIS must be able to GEORECTIFY Not always a simple task!

9. Orthorectification

10. Georegistration: Control

11. Georectification

12. Conflation

13. Address matching 2123 South Main St. Anywhere CA 93901 4,312,205mN 623,864mE 15N

14. Geographic information fundamentals 1. Volume 2. Dimensionality 3. Continuity

15. Volume 1 meter pixel 24 bit depth (8 bit R, 8 bit G, 8 bit B) California 3 rd largest State A=158,706 square miles A= 411,046,653,039 square meters N=9.865x10^10 bytes 98 gigabyte image

16. Volume Issues: Tiles and Pyramids

17. Dimensionality Simple geographic features can be used to build more complex ones. Areas are made up of lines which are made up of points represented by their coordinates. Areas = {Lines} = {Points}

18. Areas are lines are points are coordinates

19. Continuity Attributes of the earth fall into different spatial “behaviors” over space and time Many phenomena are best treated as continuous fields –E.g. air temperature, atmospheric pressure, population density Others have distinct spatial extent or edges –E.g. census tracts, buildings, roads

20. Field vs. Feature (object)

21. Fields are often rasters

22. Air Photos Discontinuous irregular rasters: resampling 1929

23. Features are often vectors

25. Properties of Features Size Distribution/density Shape Scale Orientation

26. Size: Resolution and Extent 10cm, 25cm, 50cm, 1m

27. Resels: Non-uniform Support

28. Data structure conversion

29. Distribution

30. Geographical Clustering

31. Clusters on points/networks

32. Shape

33. Shape vs. Support

34. Shape measures/analysis

35. Scale: RF vs. Detail Santa Barbara

36. Scaling behavior

37. Orientation: Objects & Frame

38. Tobler’s First Law of Geography “Everything is related to everything else but near things are more related than distant things” (Tobler, 1970) Variation of (x 1 – x 0 ) 2 Spatial autocorrelation Violates assumptions of statistics

39. Geographical relations Among features –Contains/overlaps/intersects –Contiguity/Adjacency –Proximity –Trajectory Within fields –Neighborhood relation –Pattern –Process

40. Vector polygon overlay O =

41. Raster overlay 0 1 & =

42. Buffering

43. Pattern

44. Pattern (Fourier) Analysis

45. Contiguity http://www.clearproject.net/chapter10fig5.JPG (Clear Lake, Iowa)

46. Semivariogram

47. Most important, process… G = g (x, y, z, s, A, t) t0t0 t1t1 t2t2 t3t3

48. Strands

49. Time-Space dynamics

50. Dynamics 19301950197019801990 FROM TO

51. Geography The study of the earth and its features and of the distribution of life on the earth, including human life and the effects of human activity.