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GIS Tutorial 1

GIS Tutorial 1. Lecture 4 Geodatabases. Outline. Data types Geodatabases Data table joins Spatial joins Field calculator Calculate geometry ArcCatalog functions. Lecture 4. Data types . Directly loadable data types. dBase (.dbf) Text with comma (.csv) or tab-separated values (.txt)

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GIS Tutorial 1

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  1. GIS Tutorial 1 Lecture 4 Geodatabases

  2. Outline • Data types • Geodatabases • Data table joins • Spatial joins • Field calculator • Calculate geometry • ArcCatalog functions GIS TUTORIAL 1 - Basic Workbook

  3. Lecture 4 Data types GIS TUTORIAL 1 - Basic Workbook

  4. Directly loadable data types • dBase (.dbf) • Text with comma (.csv) or tab-separated values (.txt) • Microsoft Access (.mdb) • Microsoft Excel (.xls) GIS TUTORIAL 1 - Basic Workbook

  5. Data table formats • First row must have attribute names with self-documenting labels • (e.g. Pop5To17, Area) • Usual naming convention • first character is a letter • remaining characters be any letters, digits, or the underscore character • All additional rows of a data table need to contain attribute values • None of the rows can be sums, averages, or other statistics of raw data rows GIS TUTORIAL 1 - Basic Workbook

  6. Data table formats • dBase field names • Maximum 10 characters GIS TUTORIAL 1 - Basic Workbook

  7. Lecture 4 geodatabases GIS TUTORIAL 1 - Basic Workbook

  8. Geodatabase types Manages features and tables inside a database management system • File geodatabase • stores datasets in a folder of files • each dataset a file up to 1 TB in size • can be used across platforms • can be compressed and encrypted for read-only, secure use • ESRI’s recommended choice GIS TUTORIAL 1 - Basic Workbook

  9. Geodatabase types • Personal geodatabase • stores datasets in a Microsoft Access .mdb file • storage sizes between 250 and 500 MB • limited to 2GB • only supported on Windows • some higher level GIS functions can only be performed if a geodatabase is created • ArcSDE geodatabase • stores datasets in a number of optional DBMSs: • IBM DB2, IBM Informix , Microsoft SQL Server , Oracle, or PostgreSQL • unlimited size and users GIS TUTORIAL 1 - Basic Workbook

  10. Geometric Network in a Geodatabase • Example of • higher level • GIS Function GIS TUTORIAL 1 - Basic Workbook

  11. New file geodatabase ArcCatalog: select File> New> File geodatabase or Personal geodatabase> type name of new geodatbase GIS TUTORIAL 1 - Basic Workbook

  12. Import into geodatabase Shapefile features GIS TUTORIAL 1 - Basic Workbook

  13. Import into geodatabase • Tables GIS TUTORIAL 1 - Basic Workbook

  14. Export from geodatabase GIS TUTORIAL 1 - Basic Workbook

  15. Compact geodatabases • File and personal geodatabases • Reduces size and improves performance • Compact personal geodatabases > 250 MB. • Geodatabases with frequent data entry, deletion, or general editing • Open geodatabases in ArcMap cannot be compacted • remove any layers with a source table or feature class in that database from the TOC GIS TUTORIAL 1 - Basic Workbook

  16. Compress geodatabases • File geodatabases • Once compressed, a feature class or table is read-only and cannot be edited • Compression is ideally suited to mature datasets that do not require further editing • Compressed dataset can be uncompressed to return it to its original, read-write format GIS TUTORIAL 1 - Basic Workbook

  17. View geodatabases • Cannot identify names in Windows Explorer • Must use ArcCatalog GIS TUTORIAL 1 - Basic Workbook

  18. Lecture 4 Data table joins & Relates GIS TUTORIAL 1 - Basic Workbook

  19. Data table joins • Putting two tables together to make one table • Join two tables one-to-one by row • Must have the same values and data types GIS TUTORIAL 1 - Basic Workbook

  20. Joins and Relates • Two methods to associate tables in ArcMap based on a common field • Join appends the attributes • from one on to the other table • Relate defines a relationship • between two tables GIS TUTORIAL 1 - Basic Workbook

  21. Join or Relates Usage: • Join- Assumes one-to-one or many-to-one cardinality • - Appends the attributes of the two tables • - i.e. parcel polygon table one unique permanent parcel • number (ppn) is matched to an Auditor attribute characteristic • table (property value) with one unique ppn • Relates- Assumes many-to-many or one-to-many cardinality • - Tables remain independent • - i.e. if you select a building, you can find all the tenants that • occupy that building. Similarly, if you select a tenant, you can find • what building he/she resides in (or several buildings, in the case of a • chain of stores in multiple shopping centers—a many-to-many • relationship). GIS TUTORIAL 1 - Basic Workbook

  22. Join example • Housing heating fuel study for U.S. Counties • Source: U.S. Census • Data table: Census SF3 table for heating fuel by county • Map Features: County polygons GIS TUTORIAL 1 - Basic Workbook

  23. Data table • Heating fuel table (Excel spreadsheet) GIS TUTORIAL 1 - Basic Workbook

  24. Data table • Heating fuel table data dictionary • H040001: Occupied housing units: House heating fuel; TOTAL Units • H040002: Occupied housing units: House heating fuel; Utility gas • H040003: Occupied housing units: House heating fuel; Bottled; tank; or LP gas • H040004: Occupied housing units: House heating fuel; Electricity • H040005: Occupied housing units: House heating fuel; Fuel oil; kerosene; etc. • H040006: Occupied housing units: House heating fuel; Coal or coke • H040007: Occupied housing units: House heating fuel; Wood • H040008: Occupied housing units: House heating fuel; Solar energy • H040009: Occupied housing units: House heating fuel; Other fuel • H040010: Occupied housing units: House heating fuel; No fuel used GIS TUTORIAL 1 - Basic Workbook

  25. Feature class • County polygons GIS TUTORIAL 1 - Basic Workbook

  26. Add data and features to map GIS TUTORIAL 1 - Basic Workbook

  27. Open attribute tables • Find common attribute to join GIS TUTORIAL 1 - Basic Workbook

  28. Data problem • FIPS has leading zero and is a TEXT field. • GEO_ID2 is a NUMBER fieldwith no leading zeros. GIS TUTORIAL 1 - Basic Workbook

  29. Data solution • Make a new NUMBER field in Counties attribute table and use field calculator to populate new field from old GIS TUTORIAL 1 - Basic Workbook

  30. Data solution • New FIPS_NUM is same as GEO_ID2 and ready to join GIS TUTORIAL 1 - Basic Workbook

  31. Join tables GIS TUTORIAL 1 - Basic Workbook

  32. Join result • Heating fuel data is now listed for every county in the USCounties feature attribute table GIS TUTORIAL 1 - Basic Workbook

  33. Permanent joins • Joins are temporary and can be removed • Export data to make joins permanent GIS TUTORIAL 1 - Basic Workbook

  34. Choropleth map result GIS TUTORIAL 1 - Basic Workbook

  35. Lecture 4 Spatial joins GIS TUTORIAL 1 - Basic Workbook

  36. Spatial join example • You have census block group centroids with housing fuel data • You want to know housing fuel data by neighborhoods • No attributes in common • Spatial join needed GIS TUTORIAL 1 - Basic Workbook

  37. Spatial joins • Points to polygons • Spatially joins points (block centroids) within polygons (neighborhoods) • Joins using “shape” (not attribute field) GIS TUTORIAL 1 - Basic Workbook

  38. Spatial joins • Right click polygon layer (neighborhoods) GIS TUTORIAL 1 - Basic Workbook

  39. Join result • New polygon feature GIS TUTORIAL 1 - Basic Workbook

  40. Join result • Counts and sums GIS TUTORIAL 1 - Basic Workbook

  41. Count result • Number of points in each polygon GIS TUTORIAL 1 - Basic Workbook

  42. Sum result • Every block group centroid has associated data • (e.g. H040004, heating electricity shown in labels) GIS TUTORIAL 1 - Basic Workbook

  43. Sum result • One neighborhood example • Central business district • 4 block groups • Housing units with electricity fuel (80 + 299 + 128 + 292 ) • Sum = 799 GIS TUTORIAL 1 - Basic Workbook

  44. Choropleth map result (sum) GIS TUTORIAL 1 - Basic Workbook

  45. Choropleth map result (sum) GIS TUTORIAL 1 - Basic Workbook

  46. Other spatial joins • Polygons to points • Example: ATM robberies (points) need neighborhood name GIS TUTORIAL 1 - Basic Workbook

  47. Polygon to point join result • Neighborhood name shows on each point GIS TUTORIAL 1 - Basic Workbook

  48. Other spatial joins • Points to points • Example: What is the distance of a burglary to the nearest commercial property? GIS TUTORIAL 1 - Basic Workbook

  49. Point to point join result • Distance to nearest commercial property shows on each burglary point GIS TUTORIAL 1 - Basic Workbook

  50. Lecture 4 Field calculator GIS TUTORIAL 1 - Basic Workbook

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