SAFARI 2000 Carbon in Live Vegetation, 0.5-Deg (Olson) The olson_safari.dat.gz file contains a subset of Olson's Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation: A Database. The subset is for southern Africa. Data Citation: Cite this data set as follows: Olson, J. S., J. A. Watts, and L. J. Allison. 2002. SAFARI 2000 Carbon in Live Vegetation, 0.5-Deg (Olson). Available on-line [http://www.daac.ornl.gov] from the Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. This README file contains information regarding: 1. Data format 2. Procedure used to create the southern Africa subset 3. Legend and data source ------------------------------------------------------------------- DATA FORMAT ------------------------------------------------------------------- The downloadable file, olson_safari dat.gz, is a UNIX compressed file. The data file is in ASCII Grid format for ArcInfo. The file contains a single ASCII array with integer values. Coordinates listed below are in decimal degrees. Rows 80 Columns 110 UpLeftX 5 UpLeftY 5 LoRightX 60 LoRightY -35 cellsize 0.5 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 {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. Although the nodata_value is set to -9999 in the header that value does not actually occur in the data. To import this file into ArcInfo use the following command at an ARC prompt: ASCIIGRID {INT | FLOAT} Arguments - the ASCII file to be converted. - 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. ------------------------------------------------------------------- PROCEDURE USED TO CREATE THE SOUTH AFRICAN SUBSET ------------------------------------------------------------------- The original data were converted to an ArcInfo grid 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 was the 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 ------------------------------------------------------------------- For legend information please refer to the following web page: http://cdiac.esd.ornl.gov/ftp/ndp017/table.html 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 Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) World Wide Web site: http://cdiac.esd.ornl.gov/ ========================================================================= Legend & Additional Sources of Information ------------------------------------------ The following legends are used in the original data: Median C Actual C Minimum C Maximum C Estimate Estimate Estimate Estimate Ecosystem Color-Id Ecosystem Complexes (Kg C/m2) (Kg C/m2) (Kg C/m2) (Kg C/m2) Codes -------- ----------------------------- --------- --------- --------- --------- --------- 2 Tropical/Subtropical 15.00 12.00 4.0 25.0 29,33,73 Broad-leaved Humid Forest 4 Mid-Latitude Mixed Woods 10.00 7.00 6.0 14.0 23,24 (Deciduous/Evergreen/Conifer) 7 Tropical/Subtropical Dry 7.00 6.00 5.0 9.0 32 Forest and Woodland 8 Second Growth Forest/Fields 5.00 4.00 4.0 8.0 56,57 (Tropical/Subtropical Humid, Temperate/Boreal Forests) 11 Tropical Montane Complexes 5.00 5.00 1.0 15.0 28 12 Second Growth Field/Woods 4.00 3.00 2.0 5.0 55,58 (Tropical/Temperate Woods, Fields/Grass/Scrub) 13 Succulent and Thorn Woods and 4.00 3.00 2.0 6.0 59 Scrub 14 Mediterranean Types & 4.00 3.00 2.0 8.0 46,47 Dry, Highland Woods 15 Warm or Hot Wetlands 3.00 2.00 1.0 6.0 45,72 16 Paddyland 3.00 3.00 2.0 4.0 36 17 Tropical Savanna and Woodland 3.00 3.00 2.0 5.0 43 (Interrupted Woods) 18 Shore and Hinterland 3.00 3.00 0.0 10.0 Complexes 65,66,67,68 23 Warm or Hot Shrub and 1.30 0.90 0.5 3.0 41 Grassland (Marginal Lands) 24 Cool or Cold Farms, Towns 1.00 0.70 0.4 2.0 30 25 Warm/Hot Farms, Towns, Cool 1.00 0.80 0.6 2.0 31,40 Grass/Scrub 29 Non-Polar Desert and 0.40 0.30 0.2 1.0 51,71,49 Semidesert, Sparse Vegetation 30 Non-Polar Sand Desert 0.05 0.05 0.0 0.2 50 31 Water Bodies 0.00 0.00 0.0 0.0 0 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 Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) World Wide Web site: http://cdiac.esd.ornl.gov/ [Internet Link] ------------------------------------------------------------------- ORIGINAL DATA SET CITATION ------------------------------------------------------------------- Olson, J.S., J.A. Watts, and L.J. Allison, 1985. Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation. NDP017, Carbon Dioxide Information Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee. Data available online at http://cdiac.esd.ornl.gov/ndps/ndp017.html