1. Intro to GIS October 24, 2006

2. Announcements  Second Midterm Quiz is next week (covers chapters 6, 9, 10, 12 plus lectures  Oslo Project description  GIS Club Activity: Presentation by Thorbjørn Geirbo, today at 14.15 in the GIS Lab (HHH 035)  GIS Day: Wednesday, November 15th.

3. Oslo Project Examples from 2004  Tilgjengelighet til legesentre i Bydel Grorud  Innvandrernes bosettingsmønster  Distinksjoner i Oslo: En Bourdieusk alanyse av ulikehet ved hjelp av geografiske informasonssystemer  Sosiale skiller i Oslo  Sosiale ulikheter i Oslo  Inntekt og boligstruktur i Oslo: med fokus på bydel Gamle Oslo  Privatisering og innntektsnivå i bydel Vestre Aker

4. Examples from 2005  Barnehagedekning i bydel St. Hanshaugen  En treffsted for alle unge? Tilgjengelighet til fritidsklubber i Nordstrand og Østensjø bydeler  Romlig analyse av sosiale forskjeller; segregering på Grünerløkka?  Vestre Aker – mer enn bløtkakevillaer og Jaguarer (en casebasert diskusjon av GIS som geografisk analyseverktøy)

9. Last Week’s Lecture  Database – an integrated set of data on a particular subject  Databases offer many advantages over files  Relational databases dominate

10. A DBMS contains:  Data definition language  Data dictionary  Data-entry module  Data update module  Report generator  Query language

11. Advantages of Databases  Avoids redundancy and duplication  Reduces data maintenance costs  Applications are separated from the data Applications persist over time Applications persist over time Support multiple concurrent applications Support multiple concurrent applications  Better data sharing  Security and standards can be defined and enforced

12. SQL  Structured (Standard) Query Language – (pronounced SEQUEL)  Developed by IBM in 1970s  Now de facto and de jure standard for accessing relational databases  Three types of usage Stand alone queries Stand alone queries High level programming High level programming Embedded in other applications Embedded in other applications

13. Types of SQL Statements  Data Definition Language (DDL) Create, alter and delete data Create, alter and delete data CREATE TABLE, CREATE INDEX CREATE TABLE, CREATE INDEX  Data Manipulation Language (DML) Retrieve and manipulate data Retrieve and manipulate data SELECT, UPDATE, DELETE, INSERT SELECT, UPDATE, DELETE, INSERT  Data Control Languages (DCL) Control security of data Control security of data GRANT, CREATE USER, DROP USER GRANT, CREATE USER, DROP USER

14. Spatial Relations  Equals – same geometries  Disjoint – geometries share common point  Intersects – geometries intersect  Touches – geometries intersect at common boundary  Crosses – geometries overlap  Within– geometry within  Contains – geometry completely contains  Overlaps – geometries of same dimension overlap  Relate – intersection between interior, boundary or exterior

15. Spatial Methods  Distance – shortest distance  Buffer – geometric buffer  ConvexHull – smallest convex polygon geometry  Intersection – points common to two geometries  Union – all points in geometries  Difference – points different between two geometries  SymDifference – points in either, but not both of input geometries

16. Spatial Search  Buffering is a spatial retrieval around points, lines, or areas based on distance.  Overlay is a spatial retrieval operation that is equivalent to an attribute join.

17. Identify

18. Recode OR

19. Data overlay

20. Overlay

21. Types of overlay operations  And  Or  Max  Min

22. Buffer (raster) + 1

23. Buffer (vector)

24. Complex Retrieval: Map Algebra  Combinations of spatial and attribute queries can build some complex and powerful GIS operations, such as weighting.

25. Review  A geographic database contains both spatial and tabular data. The spatial data contains feature shape and location information, while the tabular data contains the attributes for the features. Often, feature attributes are contained in multiple tables.

26. Making Maps With GIS

27. Introduction  Output is the pinnacle of GIS projects  Two main types of output Maps Maps Visualizations (see chapter 13) Visualizations (see chapter 13)  Maps are good at summarizing and communicating

28. What is a map?  “A graphic depiction of all or part of a geographic realm in which the real-world features have been replaced by symbols in their correct spatial location at a reduced scale.” power line

29. Map function in GIS  Storage  Temporary communication  Intermediate check of data  Final report

30. GIS Processing Transformations

31. Characteristics of Map  Two main types Topographic Topographic Thematic Thematic  Some map problems Can miscommunicate Can miscommunicate Each map is just one of all possible maps Each map is just one of all possible maps Complex maps can be difficult to understand Complex maps can be difficult to understand

32. Topographic Map

33. Thematic Map

39. Map Types  Point data  Line data  Area data  Volume data  Time data

40. Choosing a Map Type  Cartographers have designed hundreds of map types: methods of cartographic representation.  Not all GISs allow all types.  Most have a set of basic types  Depends heavily on the dimension of the data to be shown in the map figure.

41. Choosing the Wrong Type  Fairly common GIS error.  Due to lack of knowledge about cartographic options.  Can still have perfect symbolization.  Possibility of misinformation  Definite reduction in communication effectiveness.

42. Choropleth Class Schemes

43. Choosing Types  Check the data Continuous Continuous Discrete Discrete Accuracy & Precision Accuracy & Precision Reliability Reliability  Dimension (Point, Line, Area, Volume)  Scale of Measurement (Nominal, ordinal, etc.)  GIS capability  Is there a need to supplement GIS software? (e.g. with a drawing package)

44. Maps and Cartography  Map – ‘digital or analog output from a GIS showing information using well established cartographic conventions’  Cartography is the art, science and techniques of making maps

45. The Need for Design n To appear professional and avoid errors, GIS maps should reflect cartographic knowledge about map design. n A map has a visual grammar or structure that must be understood and used if the best map design is desired. n Cartographic conventions should be followed (e.g. forests should be green).

46. Map Design  Good map design requires that map elements be placed in a balanced arrangement within the neat line.  A GIS map is designed in a process called the design loop.  Primary goals in map design: to share information, highlight patterns and processes, and illustrate results.

47. To be effective, a map must be correctly designed and constructed.

48. The Parts of a Map: Map Elements The United States of America Alaska Lambert Conformal Conic Projection Source: U.S. Dept. of State 04123 hundreds of kilometers 04 0 4 Washington,D.C. National Capital Legend Scale Credits North Arrow Place nameInset Ground Figure Neat line BorderTitle Hawaii

49. Title Legend Projection Grid Data Source Inset map Map Body Author North Arrow Scale

50. Bertin's Graphic Primitives

54. Visual balance is key!  Visual balance is affected by:  the "weight" of the symbols  the visual hierarchy of the symbols and elements  the location of the elements with respect to each other and the visual center of the map.

55. Visual center 5% of height Landscape Portrait

56. Visual Layout Title Here Eye expects (1) balance and (2) alignment

57. Text: Selection and Placement Kristiansand BM 232 U S R o u t e 6 6 2 0 0 L a k e M u d POINTLINEAREA Some cartographic label placement conventions. Points: right and above preferred with no overlap. Lines: Following the direction of the line, curved if a river. Areas: On a gently curved line following the shape of the figure and upright. Bærum Oslo

58. Text placement Trondheim Bogstadvann Path right PathDownPathDown

59. Symbol “weight” Line weight Pattern ShadingHue

60. Map Design and GIS  When a GIS map is the result of a complex analytical or modeling process, good design is essential for understanding.  The map is what distinguishes GIS as a different approach to the management of information, so extra care should be taken to improve the final maps that a GIS generates in a GIS task.

61. Limitations of Paper Maps  Fixed scale  Fixed extent  Static view  Flat and hence limited for 3D visualization  Only presents ‘complete’ world view  Map producer-centric

62. Conclusions  Cartography is both an art and a science  Maps are fundamental to GIS projects  Modern advances in cartography make it easy to produce good and bad maps  New technology and especially the Internet has change the content and techniques of GIS-based cartography

67. Multivariate Mapping

68. Part II: Working with Attributes in ArcGIS

69. Issues to discuss  how attribute data is stored in a table of rows and columns  how attribute data is associated with features  tabular field types supported in ArcGIS  types of table relationships  how tables can be related to each other  how to join tables based on a common field

70. Anatomy of a Table  Each table in a database has the same basic format: an array of rows and columns. Rows are also called records, and columns are also called fields.  Some tables, like a feature class's default feature attribute table, have a preset number of columns. For instance, a polygon coverage's feature attribute table has four standard columns: Area, Perimeter, Coverage#, and Coverage-ID, while a line shapefile's feature attribute table has only one default column, named Shape. Other tables are completely user- defined.

72.  The table has three user-added columns: Name, Country, and Population. ArcMap automatically adds a third column (FID) for display purposes. The name of this column may be different depending on the type of data source. For example, it is called FID for a coverage or shapefile, OBJECTID for a geodatabase feature class, and Order_ID for a grid.  Because some databases and some operations do not support fields with blanks in their names, you should avoid creating fields that contain them. In addition, every column in a table should have a unique name but columns in the same table can have a variety of formats. NOTE: Norwegian “æ å ø” can also create problems, as can decimal formats (10,1 versus 10.1).

73. Tabular data field types  Tables are capable of storing date, number, and text values, but most tabular formats have several different field types to store this information.  Choosing the best field type for the values to be stored is an important consideration. Also, the available field types can vary between tabular formats. In general, you can store numbers, text, and dates. Specifically supported formats in ArcCatalog include short integer, long integer, float, double, text, date, object-id, and blob.

74. Information stored in tables is organized by fields and field types. When defining a table's fields, be aware that each database has its own rules defining what names and characters are permitted.

75. ArcGIS Tabular Formats  ArcGIS supports the use of multiple formats for storing and managing tabular data. Each of ArcGIS software's primary spatial formats has its own native format. Coverages use INFO-formatted tables; shapefiles store their attributes in dBASE (.dbf) format; geodatabases rely on the format of their supporting RDBMS (Oracle, for example).  Deciding on the proper format in which to store attribute information is an important part of database design and can affect the efficiency with which you are able to access feature attributes. To facilitate sharing data that's in different formats, ArcCatalog and ArcToolbox contain tools to convert between the various tabular formats. In addition, some formats, such as the coverage, can link to independent tables regardless of their format.

76. Tabular information can be stored in a variety of formats. In this case, feature information is stored in the coverage feature attribute table, data about the owners is stored in dBASE format, and tax information is stored in a relational database format.