Fundamentals of GIS

Lecture 17:Public Data II: Other Data Sources

Lecture notes by Austin Troy, University of Vermont © 2008

------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 http://nhd.usgs.gov/• Resolutions from 1:100k to 1:24k

National Hydrography Dataset (NHD)

Fundamentals of GIS

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• Download data

– http://viewer.nationalmap.gov/viewer/nhd.html?p=nhd

• Other tools available at http://nhd.usgs.gov/tools.html

Lecture notes by Austin Troy & Brian Voigt, University of Vermont © 2011

Fundamentals of GIS

©2009 Austin TroyNHD Data Viewer

Lecture notes by Austin Troy & Brian Voigt, University of Vermont © 2011

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

• http://datagateway.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

Click for info and metadata

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©2009 Austin Troy

• Can Define data extent by county, state, arbitrary rectangle, or custom AOI

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, 2006, 2008,

2009

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/• Metadata and standards available at

http://soildatamart.nrcs.usda.gov/SSURGOMetadata.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

http://fsgeodata.fs.fed.us/vector/index.html

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 http://www.fws.gov/wetlands/Data/WetlandCodes.html

• 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 http://www.fws.gov/wetlands/Data/Mapper.html

• Allows you to view availability status and to view/download data

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 digitalgeographic data base

• Production of maps from the TIGER® data base for allCensus 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: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.htmlFor attributes to 2000 and 1990 Censushttp://factfinder.census.govFor data in intermediate years via the American Community Surveyhttp://www.census.gov/acs/www/

Fundamentals of GIS

Lecture notes by Austin Troy & Brian Voigt, University of Vermont © 2011

TIGER Files & Census Data

• For geographic files• US Census:• http://www.census.gov/geo/www/tiger/tgrshp2010/tgrshp2010.

html • ESRI:• http://www.esri.com/data/download/census2000_tigerline/index

.html• Download 2000 U.S. Census TIGER lines files and

demographic data

• For Census data• Decennial Census (2010, 2000,….) and intermediate year

surveys (American Community Survey)• http://factfinder2.census.gov/faces/nav/jsf/pages/index.xhtml

Fundamentals of GIS

©2009 Austin Troy

Fundamentals of GIS

Fundamentals of GIS

VCGI

• State-level data– http://www.vcgi.org/

• Includes special access page for Irene-related data– http://www.vcgi.org/Irene/

Lecture notes by Austin Troy & Brian Voigt, University of Vermont © 2011

Fundamentals of GIS

©2009 Austin Troy

Fundamentals of GIS

• Includes an interactive map browser for “clipping and zipping” data

Lecture notes by Austin Troy & Brian Voigt, University of Vermont © 2011

Fundamentals of GIS

©2009 Austin Troy

For continuing data updates, check the data links page at 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

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 many others available for a price

– Gives status maps

– Can also buy bulk public data for a fee

• data.geocomm.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