Global Land Cover and USGS Classifications

Global Land Cover and USGS Classifications

Q: How do I change the default associations between the Global Land Cover values and the USGS Land Use classifications?

A: With TAP6.0.2203 or later, the Land Use module, and a Maintenance Subscription date of December 31, 2007, or later, you can use Global Land Cover (GLC) data files with TAP.

Note that all values in this example are for demonstration purposes only. You should determine appropriate settings for your application.

To use the GLC files with TAP you will need to set the configuration for the file locations.

The GLC data provides a classification for each 30x30-arcsecond grid point. The data contains 14 numeric classifications:

0	Water
1	Evergreen Needleleaf Forest
2	Evergreen Broadleaf Forest
3	Deciduous Needleleaf Forest
4	Deciduous Broadleaf Forest
5	Mixed Forest
6	Woodland
7	Wooded Grassland
8	Closed Shrubland
9	Open Shrubland
10	Grassland
11	Cropland
12	Bare Ground
13	Urban and Built-up

TAP associates each GLC value with a corresponding USGS Land Use Classification value. The default values, along with the complete list of USGS classifications, are shown below:

GLC Numerical Value	GLC Description	USGS Numerical Value	USGS Description
13	Urban and Built-up	10	Urban or Built-up Land Codes
		11	Urban: Residential
		12	Urban: Commercial and Services
		13	Urban: Industrial
		14	Urban: Transportation, Communications, and Utilities
		15	Urban: Industrial and Commercial Complexes
		16	Urban: Mixed
		17	Urban: Other
		20	Agricultural Land
11	Cropland	21	Agricultural: Cropland and Pasture
		22	Agricultural: Orchards, Groves, Vineyards, Nurseries, and Ornamental Horticultural Areas
		23	Agricultural: Confined Feeding Operations
		24	Agricultural: Other
10	Grassland	30	Rangeland
		31	Rangeland: Herbaceous
8 9	Closed Shrubland Open Shrubland	32	Rangeland: Shrub and Brush
		33	Rangeland: Mixed
6	Woodland	40	Forest Land
3 4	Deciduous Needleleaf Forest Deciduous Broadleaf Forest	41	Forest Land: Deciduous
1 2	Evergreen Needleleaf Forest Evergreen Broadleaf Forest	42	Forest Land: Evergreen
5 7	Mixed Forest Wooded Grassland	43	Forest Land: Mixed
0	Water	50	Water
		51	Water: Streams and Canals
		52	Water: Lakes
		53	Water: Reservoirs
		54	Water: Bays and Estuaries
		60	Wetland:
		61	Wetland: Forested
		62	Wetland: Nonforested
12	Bare Ground	70	Barren Land
		71	Barren Land: Dry Salt Flats
		72	Barren Land: Beaches
		73	Barren Land: Sandy Areas Other than Beaches
		74	Barren Land: Bare Exposed Rock
		75	Barren Land: Strip Mines, Quarries, and Gravel Pits
		76	Barren Land: Transitional Areas
		77	Barren Land: Mixed
		80	Tundra
		81	Tundra: Shrub and Brush Tundra
		82	Tundra: Herbaceous
		83	Tundra: Bare Ground
		84	Tundra: Wet
		85	Tundra: Mixed
		90	Perennial Snow or Ice
		91	Perennial Snow or Ice : Perennial Snowfields
		92	Perennial Snow or Ice: Glaciers

From the table you can see that the USGS Classifications have numerous sub-codes and nuances of meaning. If you want to use any of these other USGS classifications, you can edit and change the default associations.

From the TAP6 Configuration menu click the “Land Use” item, then the “GLC to USGS Classifications” item:

The 14 GLC categories are shown on the left of the “GLC to USGS” form:

For each GLC item you can use the pull-down list to associate that GLC category with the desired USGS classification.

All Land Use functions (path profiles, area coverage studies, map layers) are affected by the settings in the “GLC to USGS” association form.

The association between the GLC values and the USGS values enables the GLC data to be used with TAP just as the USGS data. For example, the Loss Template values contain signal loss values as a function of frequency and USGS Land Use classifications. When the GLC data is used, the values are translated to the USGS value based on the associations defined, and the loss values are computed from those values.

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