Other Data Types

1
Other Data Types

• INLS 110-111
• GIS Digital Information
• Uses, Resources Software Tools

2
LULC Land Use Land Cover

• Vector model Raster Models of digital data
• Federal Agency Dept of Interior
• US Geological Survey (USGS) National Mapping
  Division
• Widespread format primary scale 1250,000
• All LULC data conform to the Universal Transverse
  Mercator (UTM) projection.

3
LULC Content

• Files describe
• vegetation, water, natural surface, and cultural
  features on the land surface.
• Uses Anderson Classification System
• The USGS provides these data as part of its
  National Mapping Program.
• LULC mapping program designed to compliment
  standard topographic maps (scales of 1250,000
  some cases1100,000)

4
LULC Creation

• Manual interpretation of aerial photographs from
  NASA high-altitude missions other sources
• Secondary sources from earlier land use maps
  field surveys also used (as needed)
• Later digitized to create a national digital LULC
  database. (resulting GIRAS)

5
LULC Vector Image
Image Sourcehttp//edcwww.cr.usgs.gov/glis/graphi
cs/guide/1_250_lulc/figure1.gif
6
2 Formats Vector (GIRAS) or Raster (CTG)

• Available for most of the contiguous US Hawaii
• Distributed in the GIRAS or CTG formats through
  anonymous FTP (for free)
• FTP files are available sorted by state
• 1250,000-scale sorted by state
• 1100,000-scale sorted by state

7
VECTOR Geographic Information Retrieval Analysis
System (GIRAS)

• Fixed length records (ASCII) each may consist of
  1 to 16 data-element fields.
• Each data-element field may be one of 3 types
• 16 bit binary integer
• 32 bit binary integer or
• a string of text characters.
• file structure map header, section header, arc
  records subfile, coordinate subfile, polygon
  records subfile, file of arcs by polygon (FAP)
  subfile, text subfile and an associated data
  subfile.
• Topological Vector Model

8
RASTERComposite Theme Grid (CTG)

• Files are sequential and consist of fixed length
  records (except for header files)
• One grid cell for each logical record.
• Grid cells contain point sample of the quad where
  the center point of each cell is 200 meters apart
  from other center points in adjacent cells.
• cells mapped to the UTM projection

9
LULC Applications

• Compatible w/variety of USGS other data
• Example socioeconomic data compiled by the
  Bureau of Census can be compared to LULC data
• Frequently used in conjunction with DLG and DEM
  data to assist in
• river basin planning, barrier island change
  analysis, environmental impact statement
  preparation urban development studies.