From this page you can download various thematic maps and/or geo-referenced databases. All these maps and databases are in the public domain. The data is either in shapefile or in gridfile format. Files have been compressed using the ZIP format. The data are not projected (i.e., in latitude/longitude). The maps appear as graphics files (GIF) that can be copied and pasted into another application
| Theme | Type | Resolution | Source |
|
Altitude 30s (mask) |
30 seconds |
GTOPO30 (U.S. Geological Survey) |
|
|
Altitude 5m (mask) |
grid |
5 minutes |
GTOPO5 (U.S. Geological Survey) |
| Admin. boundaries | shape | n.a. | More info |
| Gazetteer | dbf | n.a. | U.S. National Imagery and Mapping Agency's (NIMA) database of foreign geographic feature names |
| Population density (mask) | grid | 2.5 minutes | CIESIN, Center for International Earth Science Information Network, Colombia University |
| Land cover (mask) | grid | 30 seconds | U.S. Geological Survey, Global land cover characteristics data base. Legend: USGS Land Use/Land Cover System |
The resolution is the size of each grid cell expressed as the length of one side of one (square) cell. The units are in (arc) degrees, minutes or seconds. When the cell size is small (e.g., 30 seconds), resolution is high. The size in square meters varies with latitude. A cell with a 30 seconds resolution is about 0.8 km2 at the equator and smaller at higher latitudes. High resolution files for large areas (countries) can be very large. This means that it may take a while to download these files, and that you will need a very good PC to work with them. Also the first time you open such a file, it may take a couple of minutes to load it.
A gazetteer is a list of place names and their coordinates. The files you can download here are for use in DIVA (to automatically assign coordinates to places). They should be placed in the <divadir>\gazet directory.
The file Includes three shapefiles for each country ADM0 - the country boundaries; ADM1 - first level administrative subdivisions (such as State, Department); ADM2 - second level administrative subdivision. .
Sources:
Africa: Corbett, J.D. and R.F. O’Brien,1997. The Spatial Characterization Tool – Africa Version
1.0. Texas Agriculture Experiment Station, Texas A&M University System, Blackland
Research Center Report No.97-03, CDROM Publication.
Asia: Asia population database (UC- Sta. Barbara through CIESIN).
South America: database downloaded from the CIAT website (no longer available)
Data for Europe, Russia, North America and Oceania are not yet included, but global and continental databases of country boundaries are available here.
Current and Future climate data
Do you want to map current (1960-90) and/or future (2040-59) climate data, you can download DIVA-GIS v.4 and its climate databases.
The files have been compressed and grouped in the ZIP format. You can use programs such as PKZIP or StuffIt to decompress the files.
A gridfile with "mask" indicates that the areas outside the selected country are masked out. For these areas, the value is "NODATA" (indicating the absence of data for those cells). For the other gridfiles, NODATA is only used for areas covered with water, except for the land cover grids, on which water is a separate class.
Shapefiles are ESRI shapefiles, a format used in ArcView-GIS, ArcExplorer, DIVA-GIS, among others. It can be imported to most other GIS programs. Shapefiles contain "vector" data such as points, lines, and polygons.
Gridfiles are used in DIVA-GIS. From DIVA-GIS they can be exported to a number of other grid formats including IDRISI and ArcView grids or to shapefiles. Gridfiles contain grid (raster) data. (More info on format; for developers).
A dbf (dBase file) is a database table.
This page
was developed by Luis Avila, Paul Moncada, and Robert J. Hijmans
with support from SGRP/SINGER