2009 Ohio River Basin Landcover Comparison


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Presentation given at 2009 Ohio Floodplain Managers Conference and Poster displayed at Hanover College Rivers Institute Conference

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2009 Ohio River Basin Landcover Comparison

  1. 1. Huntington DistrictLand Cover Comparison Using GIS …...and lots of SQLJoe Trimboli, MS, CFMCommunity PlannerHuntington District17 August 2009US Army Corps of EngineersBUILDING STRONG®
  2. 2. Huntington District Land Cover ComparisonNeed for Comparison  Ohio River Basin Comprehensive Report Study (ORBCRS)  www.orboutreach.com
  3. 3. Huntington District
  4. 4. Huntington District Land Cover Comparison GoalsIdentifies land use changes in the Ohio River BasinIncorporate map set into MapRecon portion of study  Create access table that links to HUC8 watershed for map creation  Create map for each land cover classification
  5. 5. Huntington District DataSources  National Land Cover Datasets of 1992 and 2001  Downloaded from USGS  Used seamless server  Template Selection  Best meta data available  USGS Watershed Layer (CORPSMAP)  CorpsMap is the USACE nationwide enterprise GIS implementation  Data source for many federal agencies
  6. 6. Huntington District Data Preparation Created mosaic raster layer using ArcMap 9.2 for each data set, 1992 and 2001 (6 template areas) Created raster of HUC8 watersheds Insured all raster’s had same projection  Matched land cover projection  Converted HUC8 data to match land cover data Insured all rasters had same cell size  Defined HUC8 raster layer to match land cover cell size
  7. 7. Huntington District HUC8 raster file reprojected and with matching cell size to land cover layers
  8. 8. Huntington District Process Verification Used various processes Evaluated data numerous times Different tools Different ways  Model Creation  Spatial Analyst Tools > Combine
  9. 9. Huntington District Model creation proved to be awkward and time consuming based on existing knowledge
  10. 10. Huntington District Found Combine tool while researching process
  11. 11. Huntington District Combine Creates new raster layer Combines multiple layers  Intersecting raster cell values Creates Discrete properties table NOT Floating Point
  12. 12. Huntington District Adds columns in attribute table that correspond to each raster layer
  13. 13. Huntington District Data Check: Identify point on map Open Attributes Table Scroll to matching pixel value Verify layers and column names
  14. 14. Huntington District Export all attribute tables to Microsoft Access
  15. 15. Huntington District Microsoft Access (SQL) Format of Personnel Geospatial Database Manipulates tables Ability to create and manipulate data  Non-spatial Tables  Creation custom queries
  16. 16. Huntington DistrictTables
  17. 17. Huntington District Land Cover Comparison GoalsIdentifies land use changes in the Ohio River BasinIncorporate map set into MapRecon portion of study  Create access table that links to HUC8 watershed for map creation  Create map for each land cover classification
  18. 18. Huntington DistrictComparable Study
  19. 19. Huntington DistrictUSGS Data Research
  20. 20. Huntington DistrictNLCD 1992-2001 Anderson Level I Cross-walk Table
  21. 21. Huntington DistrictCrosswalk Table Creation
  22. 22. Huntington DistrictOriginal Class Values from Raster Layer
  23. 23. Huntington District Cross walk tablesCreate tables from original raster layer table and corresponding USGS modified Anderson Level I table information. Created new Description.
  24. 24. Huntington DistrictUnique Anderson Class Table
  25. 25. Huntington DistrictUnique Anderson Class Table - Update
  26. 26. Huntington DistrictUnique Anderson Class Table - Update
  27. 27. Huntington District Class Table ImportanceThere must be the same number of classes in each comparison year for a DIRECT comparison  Not an issue at the larger Ohio River Basin level  Not an issue at smaller area comparisons  Issue at the HUC8 scale of comparison
  28. 28. Huntington DistrictMake Table Query
  29. 29. Huntington District HUCAnderson with Combine1Each HUC8 watershed with total Each Cell with HUC8 value code, and cell count and new class original class codes of 1992 and 2001 codes land cover
  30. 30. Huntington District Reclass Query DesignAll like values are linked between tables
  31. 31. Huntington DistrictReclass Query Results 1992
  32. 32. Huntington DistrictReclass Query Results 2001
  33. 33. Huntington DistrictTime to Merge Tables
  34. 34. Huntington DistrictInitial Merge Results
  35. 35. Huntington DistrictInitial Merge Results How do you calculate change percentage and map it?
  36. 36. Huntington DistrictSQL Formulas
  37. 37. Huntington District SQL Formulas1992 & 2001IIf(IsNull([1992reclass!COUNT]),0,[1992reclass!COUNT])ChangeRatio:IIf([1992]=0,([2001]/HUCAnderson!Total),[2001]/[1992])Percentage:IIf([2001]>[1992],[changeratio]*100,[changeratio]*-100)
  38. 38. Huntington DistrictResults
  39. 39. Huntington DistrictAlmost There…
  40. 40. Huntington DistrictSingle Class Queries
  41. 41. Huntington DistrictSingle Class Queries
  42. 42. Huntington DistrictFinal Goal
  43. 43. Huntington DistrictFinal Goal
  44. 44. Huntington District
  45. 45. Huntington District
  46. 46. Huntington District
  47. 47. Huntington District
  48. 48. Huntington District
  49. 49. Huntington District
  50. 50. Huntington DistrictAccuracy Concerns – 1992 Original
  51. 51. Huntington DistrictAccuracy Concerns - 2001
  52. 52. Huntington DistrictAccuracy Concerns – 1992 modified
  53. 53. Huntington District Resulting HypothesisThe land cover change from different sources is outside the 9% standard distribution curve of the percent change (location quotients) of the watersheds. The 90% represents the difference of equipment and seasonal variation.
  54. 54. Huntington District Land Cover Comparison1992 and 2001 land cover data was downloaded from the USGS National Map Seamless Server and reclassified based on the USGS Anderson Level I cross walk table. Both layers were then combined using ESRI ArcView and the supporting tables exported to Microsoft Access. The tables were then manipulated to extract the location quotients (LQ) for each class and joined based on HUC8 values. A HUC8 class table was created that insured a direct comparison of 7 classes.
  55. 55. Huntington District PosterA poster was from ESRI ArcMap with charts created in Microsoft Excel. Two large panels represent the Anderson Level I classified land cover for the project area. Small 7 map panels, one for each land classification,were mapped based on the standard deviation (StdDev) of the location quotients calculated in Microsoft Access. The StdDev values of the LQ’s within the 95% range were then mapped hollow. The charts reflect the raw LQ values crossing at the value of one.
  56. 56. Huntington District
  57. 57. Huntington DistrictQuestions ?
  58. 58. Huntington District Internet AtlasOhio River Comprehensive Reconnaissance Study (ORBCRS)  http://www.tinyurl.com/orbmaps  http://www.lrh.usace.army.mil/silver_jackets/ORB/thu mb.html  http://www.lrh.usace.army.mil/silver_jackets/ORB/200 9HanoverLandCoverPoster2009.pdf