SAFARI 2000 Vegetation and Soils, 1-Deg (Wilson and Henderson-Sellers) ------------------------------------------------------------------------------------ Abstract -------- The Wilson, Henderson-Sellers' Global Vegetation and Soils data set is an archive of soil type and land cover data derived for use in general circulation models (GCMs). The data were collated from natural vegetation, forestry, agriculture, land use, and soil maps. The data are archived at 1 degree latitude x 1 degree longitude resolution and include data for soil, soil reliability, primary vegetation, secondary vegetation, and land cover reliability. There are approximately fifty land cover classifications which include categories for agricultural and urban uses. The inclusion of secondary vegetation type is particularly useful is areas with cover types which may have a fragmented distribution, such as urban development. The soil type data are classified using climatically important properties for CGMs and provide color (light, medium, or dark), texture, and drainage quality of the soil. The land cover data are compatible with the soils data forming a coherent and consistent data set. Reliability data rank the land cover data on a 1 to 5 scale from high to low reliability. The soil reliability is ranked as one of the following: high, good, moderate, fair, or poor. Recommendations for the use of these data as well as more detailed information can be found in: Wilson, M.F. and A. Henderson-Sellers, 1985. A Global Archive of Land Cover and Soils Data for Use in General Circulation Climate Models. Journal of Climatology, Vol.5, 119-143. ========================================================================= Background Information ---------------------- Investigators: M.F. Wilson Ann Henderson-Sellers annhs@rmit.edu.au Project: SAFARI 2000 Data Set Title: SAFARI 2000 Vegetation and Soils, 1-Deg (Wilson and Henderson-Sellers) Site: Southern Africa Westernmost Longitude: 5 Easternmost Longitude: 60 Northernmost Latitude: 5 Southernmost Latitude: -35 Data Set Citation: Wilson, M. F., and A. Henderson-Sellers. 2002. SAFARI 2000 Vegetation and Soils, 1-Deg (Wilson and Henderson-Sellers). Available on-line [http://www.daac.ornl.gov] from the Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Southern African subset extractions of this data were performed by Oak Ridge National Laboratory: ORNL DAAC User Services Office ornldaac@ornl.gov +1 (865) 241-3952 Data Set Link: http://www.scd.ucar.edu/dss/datasets/ds767.0.html ========================================================================= Data File Information --------------------- This data set consists of 5 ASCII data files, each one with an accompanying binary image file: 1.land_rel_safari.dat -- land cover reliability data 2.soil_safari.dat -- soil data 3.soil_rel_safari.dat -- soil reliability data 4.veg_pri_safari.dat -- primary vegetation data 5.veg_sec_safari.dat-- secondary vegetation data ========================================================================= ASCII File Information ---------------------- The data file is in ASCII Grid format for ArcInfo. Each file contains a single ASCII array with integer values. Coordinates listed below are in decimal degrees. Rows 40 Columns 55 UpLeftX 5 UpLeftY 5 LoRightX 60 LoRightY -35 cellsize 1.0 Projection geographic The ASCII file consists of header information containing a set of keywords, followed by cell values in row-major order. The file format is: {NCOLS xxx} {NROWS xxx} {XLLCORNER xxx} {YLLCORNER xxx} {CELLSIZE xxx} {NODATA_VALUE xxx} row 1 row 2 . . . row n where xxx is a number, and the keyword NODATA_VALUE is optional and defaults to -9999. Row 1 of the data is at the top of the grid, row 2 is just under row 1 and so on. The end of each row of data from the grid is terminated with a carriage return in the file. To import this file into ArcInfo use the following command at an ARC prompt: ASCIIGRID {in_ascii_file} {out_grid} {INT | FLOAT} Arguments: {in_ascii_file} - the ASCII file to be converted. {out_grid} - the name of the grid to be created. {INT | FLOAT} - the data type of the output grid. INT - an integer grid will be created. FLOAT - a floating-point grid will be created. Binary File Information ----------------------- The ASCII data files have also been converted into binary image files that can be viewed in any standard image viewing package. The files are single-byte images, no header, 55 columns by 40 rows. Missing data (ASCII -9999) have been converted to the maximum value of 255. ========================================================================= Procedure Used to Create the Southern Africa Subset --------------------------------------------------- The original data were obtained and read following the directions in the original documentation. The data were converted to ASCII arrays and then imported into ArcInfo using the ASCIIGRID command. Using GRID (a raster- or cell-based geoprocessing toolbox that is integrated with ArcInfo) the SETWINDOW command was used to define the subarea of interest. This subarea was defined by identifying the bounding coordinates as follows: x_min 5 y_min -35 x_max 60 y_max 5 The "snap_grid" option of the SETWINDOW command was used. This snaps the lower-left corner of the specified window to the lower-left corner of the nearest cell in the snap_grid and snaps the upper-right corner of the specified window to the upper-right corner of the nearest cell in the snap_grid. In this case the snap_grid is an original data grid. The purpose of this is to ensure the proper registration of the newly set analysis window. The command format used is as follows: SETWINDOW x_min y_min x_max y_max original_grid Once the window was set, creating the new grid was simply a matter of setting the new subset grid equal to the original grid. subset_grid = original_grid An ASCII array was created from the new subset grid using the GRID command GRIDASCII. file.dat = GRIDASCII(subset_grid) ========================================================================= Legend & Additional Sources of Information ------------------------------------------ The following legends are used in the original data: Land Cover Classes (veg_pri_safari.dat, veg_sec_safari.dat) Code Land Cover Description ---- ---------------------- 0 Open Water 1 Inland water 2 Bog or marsh 3 Ice 4 Paddy rice 5 Mangrove (tree swamp) 10 Dense needleleaf evergreen forest 11 Open needleleaf evergreen woodland 12 Dense mixed needleleaf & broadleaf, evergreen & deciduous forest 13 Open mixed needleleaf & broadleaf, evergreen & deciduous woodland 14 Evergreen broadleaf woodland 15 Evergreen broadleaf cropland 16 Evergreen broadleaf shrub 17 Open deciduous needleleaf woodland 18 Dense deciduous needleleaf forest 19 Dense evergreen broadleaf forest 20 Dense Deciduous broadleaf forest 21 Open deciduous broadleaf woodland 22 Deciduous tree crops (temperate) 23 Open tropical Woodland 24 Woodland + shrub 25 Dense drought deciduous forest 26 Open Drought deciduous woodland 27 Deciduous shrub 28 Thorn shrub 30 Temperate meadow and permanent pasture 31 Temperate rough grazing 32 Tropical grassland + shrub 33 Tropical pasture 34 Rough grazing + shrub 35 Pasture + tree 36 Semi arid rough grazing 37 Tropical savanna (grassland + tree) 39 Pasture + shrub 40 Arable cropland 41 Dry farm arable 42 Nursery and market gardening 43 Cane sugar 44 Maize 45 Cotton 46 Coffee 47 Vineyard 48 Irrigated cropland 49 Tea 50 Equatorial rain forest 51 Equatorial tree crop 52 Tropical broadleaf forest (slight seasonality) 61 Tundra 62 Dwarf shrub (tundra transition and high altitude wasteland) 70 Sand desert and barren land 71 Scrub desert and semi desert 73 Semi desert + scattered trees 80 Urban Code and Properties of Soil Classes (soil_safari.dat) Code Color Texture Drainage ---- ----- ------- -------- 11 light coarse free 12 light intermediate free 13 light fine free 14 light coarse impeded 15 light intermediate impeded 16 light fine impeded 17 medium coarse free 18 medium intermediate free 19 medium fine free 20 medium coarse impeded 21 medium intermediate impeded 22 medium fine impeded 23 dark coarse free 24 dark intermediate free 25 dark fine free 26 dark coarse impeded 27 dark intermediate impeded 28 dark fine impeded 29 light -- poor 30 medium -- poor 31 dark -- poor 34 ice Land Cover Reliability Scores (land_rel_safari.dat) 1 - high reliability 2 - 3 - 4 - 5 - low reliability Soils Reliability Scores (soil_rel_safari.dat) 1 - high 2 - good 3 - moderate 4 - fair 5 - poor Although not all of the global categories may be represented in the subset of the data, the original legend has been retained. The original data and documentation can be obtained through the National Center for Atmospheric Research (NCAR) Scientific Computing Division (SCD) Research Data Archives: http://www.scd.ucar.edu/ [Internet Link] Original Data Set Citation: Wilson, M.F. and A. Henderson-Sellers, 1985. A Global Archive of Land Cover and Soils Data for Use in General Circulation Climate Models. ds767.0 Data Support Section, Scientific Computing Division, The National Center for Atmospheric Research, Boulder, Colorado, U.S.A. Also available on-line at http://www.scd.ucar.edu/dss/datasets/ds767.0.html