percentage of the drainage area that each province occupies. The
national coverage scale (1:7,500,000) is provided; record the local coverage
scale of the highest resolution available.
- 16. Land use: Use the Geographic Information Retrieval and Analysis
System (GIRAS) data base to record land use. GIRAS data are based on the Anderson classification
system (Anderson and others, 1976), which uses four-letter codes to describe a two-stage hierarchy of land use.
For example, in the code reference UR-Re, UR pertains to the Level I designation of "URBAN OR
BUILT-UP LAND." The second two letters following the hyphen, Re, indicate
the Level II category of "Residential." Modifications made with respect
to the Anderson system are as follows: (1) under the Level I category of
"AGRICULTURAL," the Level II category of "Cropland and Pasture" has been
separated into two categories, and cropland has been further separated
into irrigated and nonirrigated types; (2) the Level I classes of "WATER,"
"TUNDRA," and "PERENNIAL SNOW OR ICE" have been deleted; and (3) the Level
II categories "Mixed," "Other," and "Beaches" have been deleted. For
example:
Using the abbreviations listed above, record up to three of the spatially dominant
Level II land uses and the percentage of the basin upstream of the
reference location occupied by each. The national coverage scale
(1:250,000) is provided; rec ord the local coverage scale of the highest
resolution available.