Global Land Cover Datasets
Country Codes
This page provides access to and describes the GISS dataset "Global Distribution of Country Codes at 1°×1° Resolution". This data set gives the global distribution of countries/political subunits, reflecting the world scene in 1993. A companion dataset associates each code with its country/subunit. There are a total of 354 codes with unique entries for 186 countries along with a total of 168 subdivisions.
Each country has an integer code which is a multiple of 100 so that the last two digits are zero. For divisions within a country, the first three digits of the code (primary code) are those of the parent country; the last two zeros are replaced with digits that uniquely identify the subdivision (secondary code).
Nine countries or country composites have subdivisions. To have a system that accommodates use of data both before and after political re-organizations (mergers and divisions), we maintained the "country" (primary) code for the areally larger political unit and secondary codes for past or current subdivisions.
Political subunits for five countries are unchanged from Lerner et al. (1988):
- Australia (7 states)
- Canada (12 provinces)
- China (29 provinces)
- India (25 states)
- U.S.A. (50 states and 1 commonwealth)
The subdivisions of Brazil were expanded from five regions (Lerner et al. 1988) to 25 states.
The three countries with recent divisions or mergers are:
- Czechoslovakia: The composite country code is 4100. Secondary codes identify the Czech Republic (4101) and Slovakia (4102).
- Germany: The composite country code is 6000. Secondary codes identify the former German Democratic Republic (6001) and former Federal Republic of Germany (6002).
- U.S.S.R.: The composite country code is 17200. Secondary codes (17201-17215) identify what were country subdivisions and are now independent republics.
Caveats
The principal criterion for assigning a country/subdivision code to a gridbox is dominance of the political unit in the area (including water) of that gridbox, or the gridbox contains a small country not identified in any other cell. However, at 1°×1° resolution, there are ambiguities regarding locations of coastal and political boundaries.
About 30 island countries are not spatially dominant in their respective gridboxes, but have been included for completeness. Ninety-five ocean gridboxes were assigned country/subdivision codes to include coastal cities. Also assignments were made to minimize errors in the area of each country/subdivision, even if the country/subdivision may not spatially dominate the gridbox. Consider, for example, the situation in which a large country dominates a cell that it shares with a small country. Our computed areas are generally within 1% of the published areas (FAO, 1985) for large countries and within 5% for medium-sized countries.
Available Information
Items which you may download here are:
- Dataset (32 kb, gzipped ASCII)
- List of country identifiers
Reading the Data
Although similar to the other land cover datasets, the Country Codes dataset contains supplemental information. Rather than use the standard example to read the data, you should use something like the following snippet of FORTRAN code:
CHARACTER*80 INFO1, INFO2, INFO3
CHARACTER*13 CNAME(355)
INTEGER ICODE(355), IARRAY(360,180)
C
READ(10,910) INFO1
READ(10,910) INFO2
READ(10,910) INFO3
READ(10,920) IARRAY
DO 20 K=1,355
READ (11,930) ICODE(K),CNAME(K)
20 CONTINUE
C
910 FORMAT (A80)
920 FORMAT (10I8)
930 FORMAT (1X,I5,5X,A13)
C
STOP
END
Explanation of Arrays
The contents of INFO1, INFO2, and INFO3 are:
COUNTRY CODES DIMENSION = 360 X 180 SCALE = 1 OCEAN = 0 UNDEF = 9999999 MIN = 100 MAX = 25600 NUMREC = 6483 (NUMBER OF RECORDS IN DATA FILE)
The value of an element in IARRAY is a code which identifies the country name, as entered in the list of country identifiers. Ocean was set to 0 (formerly -999999).
References
- Lerner, J., E. Matthews and I. Fung 1988. Methane emission from animals: A global high-resolution database. Global Biogeochem. Cycles 2, 139-156.
