Global Terrain Slope and Aspect Data
The data include an elevation map describing median elevation in each grid cell, eight slope maps, and five aspect maps describing distributions (i.e. pixel counts) of the respective slope or aspect classes calculated for 3 arc-sec data and accumulated to 30 arc-sec and 5 min latitude/longitude grid cells respectively. A detailed description including technical details is provided in the documentation file.
The data is saved in RAR archives. More information about the RAR archive format, may be found elsewhere on the net.
Grid cell size: 5 minutes: | |
LAND MASK | |
Number of 3 arc second grid cells that belong to the land mask and fall into 5 minutes grid cells | |
ELEVATION |
|
Median elevation (meters) | |
SLOPES (view median slope) | Slope class |
0 % ≤ slope ≤ 0.5 % | |
0.5 % ≤ slope ≤ 2 % | |
2 % ≤ slope ≤ 5 % | |
5 % ≤ slope ≤ 10 % | |
10 % ≤ slope ≤ 15 % | |
15 % ≤ slope ≤ 30 % | |
30 % ≤ slope ≤ 45 % | |
Slope > 45 % | |
ASPECT (view dominant aspect) | Aspect class |
North: 0˚< aspect ≤45˚ or | |
East: 45˚ < aspect ≤ 135˚ | |
South: 135˚ < aspect ≤ 225˚ | |
West: 225˚ < aspect ≤ 315˚ | |
Undefined: Slope aspect undefined; this value is used for grids where slope gradient is undefined or slope gradient is less than 2%. | |
Grid cell size: 30 arc-seconds: | |
LAND MASK | |
Number of 3 arc second grid cells that belong to the land mask and fall into 30 arcsecond grid cells | |
ELEVATION |
|
Median elevation (meters) | |
SLOPES | Slope class |
0 % ≤ slope ≤ 0.5 % | |
0.5 % ≤ slope ≤ 2 % | |
2 % ≤ slope ≤ 5 % | |
% ≤ slope ≤ 10 % | |
10 % ≤ slope ≤ 15 % | |
15 % ≤ slope ≤ 30 % | |
30 % ≤ slope ≤ 45 % | |
Slope > 45 % | |
ASPECT | Aspect class |
North: 0˚< aspect ≤45˚ or 315˚< aspect ≤360˚ | |
East: 45˚ < aspect ≤ 135˚ | |
South: 135˚ < aspect ≤ 225˚ | |
West: 225˚ < aspect ≤ 315˚ | |
Undefined: Slope aspect undefined; this value is used for grids where slope gradient is undefined or slope gradient is less than 2%. | |
Data Citation:
Fischer, G., F. Nachtergaele, S. Prieler, H.T. van Velthuizen, L. Verelst, D. Wiberg, 2008. Global Agro-ecological Zones Assessment for Agriculture (GAEZ 2008). IIASA, Laxenburg, Austria and FAO, Rome, Italy.