1. Fundamentals of GIS Lecture 8: Selected Public Data Lecture notes by Austin Troy, University of Vermont © 2008 ------Using GIS--

2. Fundamentals of GIS ©2009 Austin Troy Part 1 US Geological Survey Data Sources

3. Fundamentals of GIS ©2009 Austin Troy DLG Digital Line Graphs; U.S. Geological Survey (USGS) Derived from either aerial photographs or from manual and automated digitizing methods. Digital representations of planimetric information: points, lines and areas Full range of attribute codes, full topological structuring, have passed quality-control.

4. Fundamentals of GIS ©2009 Austin Troy DLG Summary

5. Fundamentals of GIS ©2009 Austin Troy Transportation layerHypsography and Public land boundary layers

6. Fundamentals of GIS ©2009 Austin Troy DLG Users Guides DLG Standards documentation available at http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html Download, user guides, abstracts and metadata available for each DLG product at : http:// earthexplorer.usgs.gov http:// earthexplorer.usgs.gov Three DLG layers: hypsography, vegetation cover and roads

7. Fundamentals of GIS ©2009 Austin Troy DLG Category and Attribute Coding Attributes come in coded for in PAT tables To know what these codes signify, see web page http://rockyweb.cr.usgs.gov/nmpstds/acrodocs/dlg- 3/3dlg0798.pdf http://rockyweb.cr.usgs.gov/nmpstds/acrodocs/dlg- 3/3dlg0798.pdf Example: Vegetation Cover Layer, Item “Identity_lab” in PAT 000 0000 Outside area 070 0101 Woods or brushwood 070 0102 Scrub 070 0103 Orchard or plantation 070 0104 Vineyard 070 0105 Scattered trees 070 0106 Void area

8. Fundamentals of GIS ©2009 Austin Troy DLG-Medium Scale Example

9. Fundamentals of GIS ©2009 Austin Troy DLG-Small Scale Example

10. Fundamentals of GIS ©2009 Austin Troy DLG Availability Go to http://statgraph.cr.usgs.gov/viewer.htm http://statgraph.cr.usgs.gov/viewer.htm This shows hypsography coverage at 1:24000

11. Fundamentals of GIS ©2009 Austin Troy DLG Availability This shows vegetative coverage at 1:24000

12. Fundamentals of GIS ©2009 Austin Troy Digital Elevation Models Raster-based data structure for storing terrain data Stores regular array of points in space with spot elevation values Available for free from USGS, EROS Data Center Continuous coverage of lower 48, Hawaii and limited portions of Alaska Made from vector hypsography and hydrography data Still used by some, but no longer maintained by USGS

13. Fundamentals of GIS ©2009 Austin Troy National Elevation Dataset (NED) New-generation Digital Elevation model; is a complement, not a replacement to DEM They are seamless (not tiled); can be downloaded as a single scene for a large area Avoids terrain errors/ discontinuities at border of tiles and that they Filtering process yields fewer “artifacts;” improves quality of slopes and hydro modeling

14. Fundamentals of GIS ©2009 Austin Troy NED Here is an example of errors generated in drainage channel interpolation with an old DEM vs a NED

15. Fundamentals of GIS ©2009 Austin Troy NED Referenced to NAD83 Downloaded from seamless server as ArcGrid files Comes in one arc-second pixel size (~30 meters) for entire US Comes in 1/3 arc second (~10 meters) pixel size for much of the US too In a small number of areas is in 1/9 arc second (~3 meters) Status maps available at http://gisdata.usgs.net/website/usgs_gn_ned_dsi/viewer.htm http://gisdata.usgs.net/website/usgs_gn_ned_dsi/viewer.htm

16. Fundamentals of GIS ©2009 Austin Troy NED 10 and 30 meter coverage: from Seamless.usgs.gov

17. Fundamentals of GIS ©2009 Austin Troy NED Download: rectangle-defined areas as seamless tiles from http://seamless.usgs.gov, along with many other data types http://seamless.usgs.gov

18. Fundamentals of GIS ©2009 Austin Troy NED NED homepage : http://ned.usgs.govhttp://ned.usgs.gov NED is free for FTP downloads of under 10 megabytes Larger areas either have to be downloaded separately, or purchased as a bulk order.

19. Fundamentals of GIS ©2009 Austin Troy NED For large areas, can purchase pre-defined zones on CD/DVD

20. Fundamentals of GIS National Land Cover Data ©2009 Austin Troy

21. Fundamentals of GIS National Land Cover Data ©2009 Austin Troy Available for 1992 and 2001 21-category land cover classification scheme based on 1992 Landsat data Comes in image format 30 meter square spatial resolution Available for free from http://seamless.usgs.gov http://gisdata.usgs.net/website/MRLC/viewer.php

22. Fundamentals of GIS ©2009 Austin Troy NLCD 2001 2001 classes are somewhat different from 1992 and are not designed to be compared for many class types. E.g. “developed-open space”; many areas classed as low density urban in 1992 Hence change analysis no recommended; however later 1992 will be reclassed to allow this comparison NLCD 2006 is under plans as NLCD moves from being a mapping to a monitoring program

23. Fundamentals of GIS NLCD 1992 and 2001 classification schemes ©2009 Austin Troy Descriptions at http://www.epa.gov/mrlc/definitions.html

24. Fundamentals of GIS ©2009 Austin Troy NLCD 2001 Also includes layers of percent canopy cover and percent imperviousness. These can be downloaded or viewed through a viewer online at http://gisdata.usgs.net/website/MRLC/viewer.php http://gisdata.usgs.net/website/MRLC/viewer.php imperviousness canopy

25. Fundamentals of GIS ©2009 Austin Troy NLCD:accuracy Improved accuracy in 2001 Accuracy tables for 1992 by region available at http://www.epa.gov/mrlc/accuracy.html http://www.epa.gov/mrlc/accuracy.html 2001 accuracy tables still under development 1992 regions (EPA regions) 2001 regions/ reference points

26. Fundamentals of GIS NLCD accuracy: 1992 ©2009 Austin Troy http://landcover.usgs.gov/accuracy/

27. Fundamentals of GIS ©2009 Austin Troy DOQs Digital orthophoto quarter quadrangle Also known as DOQQ Old version is scanned photos, from the National Aerial Photography Program (NAPP) One-fourth of a 7.5-minute USGS topographic map 1 meter spatial resolution

28. Fundamentals of GIS ©2009 Austin Troy Digital Orthophoto Quadrangles Comes in three extents: 3.75 minute quarter quad (140 megs for color) 7.5 minute quad: limited availability, 140 megs for BW Seamless DOQs from http://seamless.usgs.gov http://seamless.usgs.gov

29. Fundamentals of GIS ©2009 Austin Troy The difference between an aerial photograph and an orthophoto Aerial photo –image displacement caused by tilting of camera and terrain relief –scale is not uniform –cannot measure distances on a photograph Orthophoto –rectified to remove non- constant scale due to varying distance to camera –Also adjusts for elevation and tilt –Therefore possible to measure distances directly like on other maps –Can serve as a base map onto which other info may be overlaid Light travels longer distance at scene edge: magnification

30. Fundamentals of GIS ©2009 Austin Troy DOQ Documentation Download, metadata and user guides available at http://edcsns17.cr.usgs.gov/EarthExplorer/ Standards Documentation available at http://rockyweb.cr.usgs.gov/nmpstds/doqstds.html http://rockyweb.cr.usgs.gov/nmpstds/doqstds.html

31. Fundamentals of GIS ©2009 Austin Troy Scanned image of a U.S. Geological Survey (USGS) standard series topographic map The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The map is scanned at a minimum resolution of 250 dots per inch Digital Raster Graphics

32. Fundamentals of GIS ©2009 Austin Troy Used on-screen to collect, review, and revise other digital data, especially digital line graphs, DLG. DRG’s are available at www.gisdatadepot.com and at www.mapmart.com; some state GIS repositories have them too for freewww.gisdatadepot.comwww.mapmart.com

33. Fundamentals of GIS ©2009 Austin Troy This database contains information about almost 2 million physical and cultural geographic features in the United States. The Federally recognized name of each feature described in the data base is identified, and references are made to a feature's location by State, county, and geographic coordinates. Point coordinates are given in latitude/longitude Often abstracts large features to a point USGS Geographic Names Information System (GNIS)

34. Fundamentals of GIS ©2009 Austin Troy Includes location, names and category of features such as: Schools/universities Churches/cemeteries Airports/ports Parks/recreation centers Shopping centers Stadiums/arenas Theaters/auditoriums/cultural facilities Country clubs/golf courses Marinas/yacht clubs Trailheads (some) Rural fire stations (some) Dams/reservoirs Cities/incorporated areas (as points) GNIS

35. Fundamentals of GIS ©2009 Austin Troy Information, downloads and a query engine available at: http://geonames.usgs.gov http://geonames.usgs.gov Files export as zipped text file. Can be imported into Excel The query engine can tell you the following about any named geographic feature you input: Latitude/longitude Elevation Estimated 1994 population of cities Feature type GNIS

36. Fundamentals of GIS ©2009 Austin Troy Part 2 Data from Other Sources

37. Fundamentals of GIS ©2009 Austin Troy Comes from both the USGS and the EPA Surface water features: lakes, ponds, streams, rivers, springs Nationally consistent Order of linkages coded to allow for flow path analysis Background info at http://nhd.usgs.gov/techref.html http://nhd.usgs.gov/techref.html Resolutions from 1:100k to 1:24k National Hydrography Dataset (NHD)

38. Fundamentals of GIS ©2009 Austin Troy NHD Many analysis tools designed for this data. For instance: can find the path upstream or downstream from any point using NHD data and network analyst; flow reaches are numbered sequentially in order of flow to allow path analysis Stream reaches encoded like addresses on a street Connections encoded using topology Other tools available at http://nhd.usgs.gov/tools.htmlhttp://nhd.usgs.gov/tools.html

39. Fundamentals of GIS ©2009 Austin Troy NHD Download at http://nhdgeo.usgs.gov/viewer.htm http://nhdgeo.usgs.gov/viewer.htm

40. Fundamentals of GIS ©2009 Austin Troy NHD Can extract by County/state. Click on radio button of geography for clip Use check marks to make layers visible in base map Then Click on clip boundary (e.g. Chittenden County) in the map viewer

41. Fundamentals of GIS ©2009 Austin Troy NHD Can then choose the resolution and the database type Must turn popup blocker off to use Then get an email for custom download

42. Fundamentals of GIS ©2009 Austin Troy NHD Contents of Geodatabase: many feature classes with different purposes Many will often be empty

43. Fundamentals of GIS ©2009 Austin Troy USDA Data USDA houses a number of data layers at their new Geospatial data gateway http://datagateway. nrcs.usda.gov/http://datagateway. nrcs.usda.gov/

44. Fundamentals of GIS ©2009 Austin Troy USDA Gateway Includes CLU farm boundaries (not any longer, but SAL has it for VT)) Hydrologic Units (8 and 12 digit) NED elevation Digital Raster Graphics High resolution color orthophotos from 2003, 2004, 2006 (National Agriculatural Imagery Program) Geographic Names Cropland data layer (for some areas) NRCS Soils data and soils tables Climate Data (precipitation and temp)

45. Fundamentals of GIS ©2009 Austin Troy USDA Gateway Includes

46. Fundamentals of GIS ©2009 Austin Troy USDA Gateway Includes Can Define clip regions by state or county Can also highlight a layer and get information

47. Fundamentals of GIS ©2009 Austin Troy Common Land Units Farm field boundaries representing smallest contiguous unit of cultivated land For farms in USDA programs Much more accurate that “agriculture” category in NLCD land cover Type of crop is unknown

48. Fundamentals of GIS ©2009 Austin Troy NAIP National Agricultural Imagery Program Digital Imagery, mosaiced by county, used by the NRCS and FSA to look at compliance with subsidy programs Ortho-rectified, Color, 1:40,000 scale 2003 and 2004

49. Fundamentals of GIS ©2009 Austin Troy SSURGO Soils Data SSURGO: Soil Survey Geographic Data from NRCS Soils data also at http://soildatamart.nrcs.usda.gov/Defa ult.aspx http://soildatamart.nrcs.usda.gov/Defa ult.aspx Metadata and standards available at http://soildatamart.nrcs.usda.gov/SSU RGOMetadata.aspx http://soildatamart.nrcs.usda.gov/SSU RGOMetadata.aspx Entails both a polygon layer showing soils area boundaries, but also an Access Database of numerous soil attributes

50. Fundamentals of GIS ©2009 Austin Troy SSURGO Soil Data Mart interface Access—sample tables; there are dozens

51. Fundamentals of GIS USDA Forest Service Data Gateway For each National Forest includes layers like: boundaries, trails, roads, ranges for certain tree and animal species, and ecological regions ©2009 Austin Troy http://svinetfc4.fs.fed.us/vectorgateway

52. Fundamentals of GIS ©2009 Austin Troy National Wetlands Inventory From Fish and Wildlife Service Maps all class 1 and 2 major wetlands Available digitally for much of the country 1:24,000 or smaller Involves a complex taxonomy of wetlands codes available at http://www.fws.gov/wetlands/_documents/gNSDI/WetlandsDeepwaterHabitatsClassification.pdf http://www.fws.gov/wetlands/_documents/gNSDI/WetlandsDeepwaterHabitatsClassification.pdf Calculator at http://www.fws.gov/wetlands/data/webatx/atx.html http://www.fws.gov/wetlands/data/webatx/atx.html Includes marine, estuarine, riverine, lacustrine and palustrine types

53. Fundamentals of GIS ©2009 Austin Troy

54. Fundamentals of GIS ©2009 Austin Troy NWI Wetlands map interface at http://wetlandsfws.er.usgs.gov/wtlnds/launch.html http://wetlandsfws.er.usgs.gov/wtlnds/launch.html Allows you to view online data and download First shows status availability map:

55. Fundamentals of GIS ©2009 Austin Troy NWI Can make PDFs easily

56. Fundamentals of GIS ©2009 Austin Troy NWI NWI by wetland type overlaid on NHD streams layer

57. Fundamentals of GIS ©2009 Austin Troy Topologically Integrated Geographic Encoding and Reference System Automates the mapping and related geographic activities required to support the decennial census and sample survey programs of the census bureau starting with the 1990 decennial census. The Census TIGER ® system supports: Creation and maintenance of the digital geographic data base that includes complete coverage of the United States and its territories TIGER

58. Fundamentals of GIS ©2009 Austin Troy The TIGER system provides support for: Creation and maintenance of a nation wide digital geographic data base Production of maps from the TIGER ® data base for all Census Bureau enumeration and publication programs Allows for address geocoding Can be integrated with Census attribute databases easily

59. Fundamentals of GIS ©2009 Austin Troy Accuracy and Attribution: TIGER has good attribution, but poor accuracy They are based partially on 1:100,000 DLG Are often conflated This is often used to assign the attributes from TIGER ® data to 1:24,000 DLG data

60. Fundamentals of GIS ©2009 Austin Troy The TIGER files contain data describing three feature types: Line Features 1.Roads 2.Railroads 3.Hydrography 4.Transportation and Utility Lines Boundary Features 1.Statistical boundaries, such as census tracts and blocks 2.Local government boundaries, such as places and counties 3.Administrative boundaries, such as congressional and school districts Landmark Features 1.Point landmarks, such as schools and churches 2.Area landmarks, such as parks and cemeteries 3.Key geographic locations, such as apartment buildings and factories

61. Fundamentals of GIS ©2009 Austin Troy TIGER line files and the demographic files Direct linkage using keys built up from: State FIPS code County FIPS code Tract number Block group number Block number

62. Fundamentals of GIS ©2009 Austin Troy For geographic files ESRI: http://www.esri.com/data/download/census2000_tigerline/index.html Download 2000 U.S. Census TIGER lines files and demographic data UC Berkeley Tiger Server: http://sunsite.Berkeley.EDU/GovData/info/tiger.html For attributes to 2000 and 1990 Census http://factfinder.census.gov For data in intermediate years via the American Community Survey http://www.census.gov/acs/www/

63. Fundamentals of GIS ©2009 Austin Troy

64. Fundamentals of GIS ©2009 Austin Troy

65. Fundamentals of GIS ©2009 Austin Troy Introduction to GIS

66. Fundamentals of GIS ©2009 Austin Troy For continuing data updates, check the data links page at http://www.uvm.edu/envnr/gradgis/supplement.html http://www.uvm.edu/envnr/gradgis/supplement.html Here you’ll find links to many state level GIS online data repositories plus many of the ones mentioned here Another link is to map a network drive to \\zoofiles\gisdata where you’ll find: NAIP imagery, ortho photos, all VCGI data plus VTrans database, World data from ESRI, DRG topo maps, Street maps USA

67. Fundamentals of GIS ©2009 Austin Troy VCGI The web site offers many layers through a browser

68. Fundamentals of GIS ©2009 Austin Troy Includes an interactive map browser for “clipping and zipping” data

69. Fundamentals of GIS ©2009 Austin Troy Other sources for USGS data www.mapmart.com –Allows users to choose tiles and layers with a geographic interface –Most public data are free, but,any others available for a price –Gives status maps –Can also buy bulk public data for a fee www.gisdatadepot.com –Not as user friendly –Just a plain old interface that is hard to navigate –However, many free data layers and lots of scripts and extensions