Fundamentals of GIS Lecture 17: Public Data II: Other Data Sources Lecture notes by Austin Troy, University of Vermont © Using GIS--
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 Resolutions from 1:100k to 1:24k National Hydrography Dataset (NHD)
Fundamentals of GIS ©2009 Austin Troy NHD Many analysis tools designed for this dataset. 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
Fundamentals of GIS ©2009 Austin Troy NHD Download at
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
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 for custom download
Fundamentals of GIS ©2009 Austin Troy NHD Contents of Geodatabase: many feature classes with different purposes Many will often be empty
Fundamentals of GIS ©2009 Austin Troy USDA Data USDA houses a number of data layers at their new Geospatial data gateway nrcs.usda.gov/ nrcs.usda.gov/
Fundamentals of GIS ©2009 Austin Troy USDA Gateway Includes CLU farm boundaries (not any longer, but Spatial Analysis Lab has it for VT) Hydrologic Units (8 and 12 digit) NED elevation Digital Raster Graphics (DRG) High resolution color orthophotos from 2003, 2004, 2006 (National Agricultural Imagery Program) Geographic Names Cropland data layer (for some areas) NRCS Soils data and soils tables Climate Data (precipitation and temperature)
Fundamentals of GIS ©2009 Austin Troy USDA Gateway Includes
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
Fundamentals of GIS ©2009 Austin Troy Common Land Units (CLU) Farm field boundaries representing smallest contiguous unit of cultivated land For farms in USDA programs Much more accurate than “agriculture” category in NLCD land cover Type of crop is unknown
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, 2004, & 2008
Fundamentals of GIS ©2009 Austin Troy SSURGO Soils Data SSURGO: Soil Survey Geographic Data from NRCS Soils data also at ult.aspx ult.aspx Metadata and standards available at RGOMetadata.aspx RGOMetadata.aspx Entails both a polygon layer showing soils area boundaries, but also an Access Database of numerous soil attributes
Fundamentals of GIS ©2009 Austin Troy SSURGO Soil Data Mart interface Access—sample tables; there are dozens
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
Fundamentals of GIS ©2009 Austin Troy National Wetlands Inventory (NWI) From U. S. 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 SDI/WetlandsDeepwaterHabitatsClassificatio n.pdf SDI/WetlandsDeepwaterHabitatsClassificatio n.pdf Calculator at Includes marine, estuarine, riverine, lacustrine and palustrine types
Fundamentals of GIS ©2009 Austin Troy
Fundamentals of GIS ©2009 Austin Troy NWI Wetlands map interface at Allows you to view online data and download First shows status availability map:
Fundamentals of GIS ©2009 Austin Troy NWI Can make PDFs easily
Fundamentals of GIS ©2009 Austin Troy NWI NWI by wetland type overlaid on NHD streams layer
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
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
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 TIGER
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
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
Fundamentals of GIS ©2009 Austin Troy For geographic files ESRI: Download 2000 U.S. Census TIGER lines files and demographic data UC Berkeley Tiger Server: For attributes to 2000 and 1990 Census For data in intermediate years via the American Community Survey
Fundamentals of GIS ©2009 Austin Troy
Fundamentals of GIS ©2009 Austin Troy
Fundamentals of GIS ©2009 Austin Troy
Fundamentals of GIS ©2009 Austin Troy For continuing data updates, check the data links page at 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
Fundamentals of GIS ©2009 Austin Troy VCGI The web site offers many layers through a browser
Fundamentals of GIS ©2009 Austin Troy Includes an interactive map browser for “clipping and zipping” data
Fundamentals of GIS ©2009 Austin Troy Other sources for USGS data –Allows users to choose tiles and layers with a geographic interface –Most public data are free, but many others available for a price –Gives status maps –Can also buy bulk public data for a fee –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