The document describes various models and operations used in GIS, including vector, raster, object models and common vector analysis operations such as selection, dissolve, append, clip, intersect, and union. It provides examples of how each operation works and the input and output layers involved. Key points covered include how topology is maintained in vector models, attributes can be linked as objects, and how selection and overlay operations can be used to analyze spatial relationships between layers.

1. Data Storage and ProcessingGIS Topics and Applications

2. GIS Models Over TimeSimple RepresentationCAD modelData AnalysisRaster modelData CollectionVector modelRelational and RulesObject model

3. nodeBnodeCPolygonIPolygonIIInodeAPolygonIInodeEnodeFnodeDPolygonVPolygonIVnodeGCoding Vector GISYou’ve seen this before.Let’s break it down.Vector Mode Model of RealityReality

4. nodeBnodeCPolygonIPolygonIIInodeAPolygonIInodeEnodeFnodeDPolygonVPolygonIVnodeG

5. nodeBnodeCPolygonIPolygonIIInodeAPolygonIInodeEnodeFnodeDA topologic vector model records the points and linesshared between polygons as unique items, thus every oneof the points and lines are recorded in the data only once.

6. nodeBnodeCnodeAPolygonIInodeEnodeDPolygon 2 is on the right sideof the line ABCED.

7. PolygonIPolygonIIInodeAPolygonIInodeEnodeFnodeDPolygonVPolygonIVPolygon 2 knows it’s adjacentto Polygons 1, 3, & 4.It shares a line segment with each. Polygon 2 knows it touchesPolygon 5.It shares node E with Polygon 5.

8. nodeBnodeCPolygonIPolygonIIInodeAPolygonIInodeEnodeFnodeDPolygonVPolygonIVnodeGStrict TopologyFeatures are composed from a common set of points and lines.Altering the vertices of one polygon affects polygons that share those vertices. Harder to introduce gaps or slivers.

9. ObjectsGIS Features as Objects is a recent method of representing aspects of the real-world in GISExample of the shift from specialty data to DBMS that are spatially-awareNon-planar, temporally shifting, topologically linked, rule-based actionsStill important to check for topology to ensure as a quality control step

10. Vector Geometry as ObjectsParcelsPlanar geometries with attribute informationParcels as objects in a Cadastral “carpet”Objects with topology rules (“don’t overlap, unless”)Members of “regional” features (zoning, municipality)Composed of surveyed parts (COGO, benchmarks)Keys that link to attribute tables (owner(s), assessments, plans, etc)

11. Cadastre Examplesurvey (COGO)parcelszonesbenchmark

12. Attributes as ObjectsNot only can multiple sets of geospatial features interact with rules, the attributes can be linked with one another, with their own set of rules and actionsOwnership record linked to GIS parcelSearch on multiple owners, recordsRemoval of parcel warns about “orphan” ownerFunctions that can be performed by GIS analyst can be embedded in the actual database

13. Manipulating Vector Mode Databases

14. Common OperationsSelection by Attributes or LocationDissolveAppendClipIntersectUnion

15. Select by AttributesCreate WHERE clauses that match a subset of the features in a vector dataset. WHERE clauses are a part of Structured Query Language (SQL)Analogous to "Find" in some other software.Match all records where…"COUNTY" = 'Gloucester'NOT "TYPE" = 'Wetlands'"POP2000" > 100000

16. Select by LocationProximity or overlay based on features in one layer and features in another layer or the same layer.Several methods to compare proximity & overlayDistance fromTouching (on edge)Contains or WithinPartial OverlapsExact Matches

17. Dissolve

18. Dissolve FeaturesInputOutput

19. Append

20. Layers to Append Input Layer 1Input Layer 2Appended LayersOverlapping Polygons/Polylines are preserved!

21. Clip

22. Input Layer & Clipping LayerClip PolygonInput LayerClipped FeaturesOutput Layer

23. Intersect

24. IntersectionWhere are the Road segments that are in flood prone areas.Select flood prone from Input Layer 1Intersect roads and flood prone [Layer 2].

25. Input Layer 2RoadsIntersect FeaturesInput Layer 1StreamFloodProneNo FloodPanel 1

26. Intersect FeaturesInput Layer 1StreamFloodProneQuestion: where are the road segments that pass through flood prone areas?No FloodInput Layer 2RoadsPanel 1

27. Intersect FeaturesInput Layer 1StreamFloodProneNo FloodSelect flood prone areas and then intersect Input Layer 1 with Layer 2 Roads.Input Layer 2RoadsPanel 2

28. Intersect FeaturesOutput Layer RoadsFloodProneStudy AreaRoads that pass through flood prone areas. Attributes of both layers maintained in table.Length of roads in flood areas becomes attributePanel 3

29. IntersectionWhere are the places that are residential and flood prone?Select flood prone from Input Layer 1Select residential from Input Layer 2Intersect

30. Intersect FeaturesInput Layer 1StreamFloodProneNo FloodPanel 1

31. Intersect FeaturesInput Layer 2ResidentialCommercialIndustryPanel 2Open space

32. Intersect FeaturesInput Layer 1StreamFloodProneNo FloodInput Layer 2ResidentialCommercialIndustryPanel 3Open space

33. Intersect FeaturesOutput LayerResidential &Flood ProneExtentPanel 4

34. Panel 2Panel 1Panel 3Panel 4

35. Union

36. Panel 1Agricultural Land UseCornGreen BeansTomatoesWheat

37. Panel 2Soil QualityPoorFairGoodExcellent

38. Panel 3Agricultural Land UseCornGreen Beans & PoorCorn &PoorGreen BeansTomatoesCorn & ExcellentGreen Beans & FairWheatTomatoes & FairWheat & ExcellentSoil QualityPoorWheat & GoodFairTomatoes & GoodGoodExcellent

39. Let’s See How It Works

40. Dissolve

41. 1. Right Click2. Click to select.Dissolve Operation

42. 2. Click to open Add Field dialog1. Click to open menuAddFieldforDissolve

43. Type a name and click OKNameandTypeofFieldforDissolve

44. Table with Code FieldResultingfield

45. DoubleClickClickClickDotheDissolve

46. 1234DissolveDialog

47. Dissolve

48. ClickDoubleClickClickAppendOperation

49. 1234AppendDialog

50. AppendTwo layers before appendOne layer after append

51. ClickClickDoubleClickClipOperation

52. 123ClipDialog

53. ClippingRoads before clippingRoads after Clipping

54. Intersection

55. Intersection ProcedureWhere are the areas that are residential in land use and flood prone?Select flood prone areas from flood prone layerSelect residential areas from land use layerDo intersection

56. Intersect

57. Residential

58. SelectbyAttributesDialogSelecting flood prone and water areas

60. SelectbyAttributesDialogSelecting residential areas

63. ClickClickDoubleClickIntersectionOperation

64. 123456IntersectionDialogRemember, if you did a selection, then get input features from drop down or drag into dialog from TOC

65. IntersectionResult

66. IntersectionResult

67. Union

68. ClickClickDoubleClickUnionOperation

69. 12345UnionDialog

70. This map depicts land use patterns for a portion of Washington Township prior to performing the union operation in which land use and flood prone layers were overlain.This map depicts land use patterns for a portion of Washington Township after performing the union operation in which land use and flood prone layers were overlain. Notice that some of the land use polygons have been cut creating new polygons. This occurs in areas in which a polygon from the flood prone layer intersects a land use polygon. The attributes of the new layer enable the analyst to map the coincidence of each land use category with each flood proneness category.