3. Methods and construction of variables
4. Files and variables
5. Access to datasets
These data are provided on an "as-is" basis and their accuracy is not guaranteed by the World Bank. All errors are the authors' own. The user acknowledges that no claims, implicit or explicit, are made for the database and that any conclusions or inferences drawn from the data are wholly the responsibility of the user. No conclusions or inferences drawn from the data or accompanying materials should be attributed to the World Bank Group, its Board of Executive Directors, its management, or any of its member countries. The boundaries, denominations, and other information contained in these data do not imply any judgment on the part of The World Bank concerning the legal status of any territory or the endorsement or acceptance of such boundaries.
These data may not be sold or used for commercial purposes.
Back to top -->
2. Citations: These data should be cited as:
World Bank. 2007. At Loggerheads? dataset v1.0. Development Research Group, World Bank.
The data contain derived versions of other datasets. Users of variables derived from those datasets should cite the sources as follows. Users are also advised to check for updated versions of those source datasets.
Population data:These data are derived from GRUMP (alpha version), with the following sources:
CIESIN (Center For International Earth Science Information Network), IFPRI (International Food Policy Research Institute), World Bank, and CIAT (Centro Internacional De Agricultura Tropical). 2004a. "Global Rural-Urban Mapping Project (GRUMP), Alpha Version: Land Area Grids." Columbia University, Socioeconomic Data and Applications Center (SEDAC), Palisades, N.Y. [http://sedac.ciesin.columbia.edu/gpw]. Accessed December 22, 2005.
———. 2004b. "Global Rural-Urban Mapping Project (GRUMP), Alpha Version: Population Grids." Columbia University, Socioeconomic Data and Applications Center (SEDAC), Palisades, N.Y. [http://sedac.ciesin .columbia.edu/gpw]. Accessed February 7, 2006.
———. 2004c. "Global Rural-Urban Mapping Project (GRUMP), Alpha Version: Urban Extents." Columbia University, Socioeconomic Data and Applications Center (SEDAC), Palisades, N.Y. [http://sedac.ciesin.columbia.edu/gpw]. Accessed December 22, 2005.
Terrestrial Ecoregions data WWF (World Wildlife Fund). 2001. "Terrestrial Ecoregions GIS Database." [http://www.worldwildlife.org/science/data/terreco.cfm]. Accessed May 25, 2005.
Described in Olson, D. M, E. Dinerstein, E.D. Wikramanayake, N.D. Burgess, G.V.N. Powell, E.C. Underwood, J.A. D'amico, I. Itoua, H.E. Strand, J.C. Morrison, C.J. Loucks, T.F. Allnutt, T.H. Ricketts, Y. Kura, J.F. Lamoreux, W.W.Wettengel, P. Hedao, & K.R. Kassem. 2001. Terrestrial Ecoregions of the World: A New Map of Life on Earth. BioScience 51:933-938
Back to top -->
3. Methods and construction of variables.
These are described in At Loggerheads?, Appendix B, pp. 240-246, downloadable at www.worldbank.org/tropicalforestreport. Relevant portions are reproduced below.
The Global Land Cover 2000 (GLC2000) database (ECJRC 2003) was used for information about land use and forest cover throughout the tropics. This database is based on 1-kilometer resolution data from the SPOT-4 satellite. Dates for the data range from 1 November 1999 to 31 December 2000. The 23 land cover classifications used by the
GLC2000 are shown in appendix table B.1, along with this report’s 7-class aggregation of these classifications.
Table B.1 GLC2000 Land Cover Categories
Code Type of land cover Aggregated land cover class
1 Tree cover, broadleaved, evergreen Forest
2 Tree cover, broadleaved, deciduous, closed Forest
3 Tree cover, broadleaved, deciduous, open Forest
4 Tree cover, needle-leaved, evergreen Forest
5 Tree cover , needle-leaved, deciduous Forest
6 Tree cover, mixed leaf type Forest
7 Tree cover, regularly flooded, fresh water Forest
8 Tree cover, regularly fl ooded, saline water Forest
9 Mosaic of tree cover and other natural vegetation Forest
10 Tree cover, burnt Forest
11 Shrub cover, closed-open, evergreen Bush
12 Shrub cover, closed-open, deciduous Bush
13 Herbaceous cover, closed-open Bush
14 Sparse herbaceous or sparse shrub cover Bush
15 Regularly fl ooded shrub and/or herbaceous cover Bush
16 Cultivated and managed areas Agriculture
17 Mosaic of cropland, tree cover, and other natural vegetation Mosaic
18 Mosaic of cropland, shrub, and/or grass cover Mosaic
19 Bare areas Bare
20 Water bodies Water/missing
21 Snow and ice Water/missing
22 Artificial surfaces and associated areas Artificial
23 No data Water/missing
Source: ECJRC 2003; authors’ aggregations.
Forest Situation Typology
The report defines human-affected rural gridcells as being in "agriculture"or "mosaic" classes (using the 7-class aggregation). It then measures the distance from these collections of cells to areas that are forest or bush in the aggregated classification. The nearest 6 kilometers are called forest edge or savanna edge depending on biome.
Forest or bush cells more than 6 kilometers from the nearest human-affected
cells are designated as forest core or savanna core. But a special rule is applied to small patches of forest and bush cells—those less than 8 square kilometers—that are completely surrounded by agriculture and mosaic cells. These are designated embedded forests. Mosaic forests consist of embedded forests and mosaic cells. Mosaiclands consist of mosaic forests and agricultural cells.
Rural Population Density
The report uses population density figures calculated from the GRUMP (alpha version) population count grid (CIESIN and others 2004b) and the GRUMP area grid (CIESIN and others 2004a). These figures are based on census data reported at a local administrative level—usually the equivalent of a county or municipio, or smaller.
Within the administrative unit, GRUMP identifies the population living in cities, towns, and villages of about 2,500 people or more (CIESIN and others 2004c). The rural remainder is assumed to be evenly distributed across the rest of the administrative unit.
The assumption of even distribution likely overstates the population density of forested and remote areas of the unit and understates the density of agricultural and mosaic areas. So the forest population densities reported here should be taken with caution—as with all global, spatially explicit population datasets.
WWF (2001) distinguishes 13 biomes. This report’s "forests" comprise three WWF tropical and subtropical biomes: moist broadleaf forest, dry broadleaf forest, and coniferous forest. This report’s "savannas" correspond to WWF tropical and subtropical grasslands, savannas, and shrublands.
Back to top -->
4. Files and variables:
- North (lac1n) begins with 1 (originally from Goode's Homolosine region 3)
- South, close to equator (lac1s) begins with 2 (originally from Goode's Homolosine region 6)
- South, far from equator (lac2s) begins with 3 (originally from Goode's Homolosine region 6)
- Northwest (afrnw) begins with 4 (originally from Lambert, 20 east, 5 south)
- Northeast (afrne) begins with 5 (originally from Lambert, 20 east, 5 south)
- South (afrs) begins with 6 (originally from Lambert, 20 east, 5 south)
- West (asiaw) begins with 7 (originally from Goode's Homolosine region 4)
- East (asiae) begins with 8 (originally from Goode's Homolosine region 4)
- South (asias) begins with 8 (originally from Goode's Homolosine region 8)
Back to top -->
5. Database access:
Disk 1_Set 1: 130mb Disk 2_Set 1: 1,217mb
Disk 1_Set 2: 130mb Disk 2_Set 2: 509mb
Disk 1_Set 3: 214mb Disk 2_Set 3: 458mb