This data set contains global, spatially explicit (1 km2 grid cells) and temporally explicit (semi-monthly) modeled output of fuel loads over southern Africa. The fuel types considered in the data set are litter (dead tree leaves), dead grass, green grass, and small-diameter twigs. The Production Efficiency Model (PEM) was used to produce the estimated fuel loads for southern Africa for the 1999-2000 growing seasons. In order to accommodate the southern African growing season, which spans October to May, the PEM was run on twenty-four 15-day intervals from September 1, 1999 to August 31, 2000. The fuel load model was calibrated from measurements recorded in 1996 along the Kalahari Transect, and has been verified from independent site measurements of fuel loads recorded during the SAFARI 2000 dry season field campaign in August and September of 2000 (Alleaume et al., 2003, Hely et al., 2003a) as well as other past campaigns.
This data set consists of gridded binary image files. The single-byte images have a 1 km resolution and the grid is 3900 columns by 4800 rows in size. There are 24 files each for litter, dead grass, and green grass fuel loads, and a single file for the twig fuel loads. For the latter, small twigs (less than 1cm in diameter) are calculated from the tree cover percentage (UMD Tree Cover from Hansen et al., 2000) using an empirical relationship (Alleaume et al., 2003). Therefore, this fuel type is a constant throughout the year.
Cite this data set as follows:
Hely C., K. K. Caylor, P. Dowty, R. J. Swap, and H. H. Shugart. 2004. SAFARI 2000 Modeled Fuel Load in Southern Africa, 1999-2000. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/755.
Alleaume, S., C. Hely, J. Le Roux, S. Korontzi, R. J. Swap, H. H. Shugart, and C. O. Justice. 2003. Using MODIS to evaluate heterogeneity of biomass burning and emissions in Southern African savannas: Etosha National Park Case Study. Int. J. Rem. Sens. Accepted.
Hely, C., S. Alleaume, R. J. Swap, C. Justice, and H. H. Shugart. 2003a. SAFARI-2000 characterization of fuels, fire behavior, combustion completeness, and emissions from experimental burns in infertile grass savannas in western Zambia. J. Arid Env. 54(2): 381-394.
Hely C., P. Dowty, S. Alleaume, K. K. Caylor, S. Korontzi, R. J. Swap, H. H. Shugart, and C. O. Justice. 2003b. Regional fuel load for two climatically contrasting years in southern Africa. J. Geophys. Res. 108(D13): 8475 doi:10.1029/2002JD002341.
Hely C., K. K. Caylor, S. Alleaume, R. J. Swap, and H. H. Shugart. 2003c. Release of gaseous and particulate carbonaceous compounds from biomass burning during the SAFARI 2000 dry season field campaign. J. Geophys. Res. 108(D13): 8470.
This data set consists of 73 separate gridded binary image files. The single-byte images have a 1 km resolution and the grid is 3900 columns by 4800 rows in size. For litter, dead grass, and green grass fuel loads, there are two image files per month for each fuel source, representing the first half and the second half of the month, respectively, and showing temporal changes in fuel loads during the study period. There is a single file for the twig fuel loads. Because small twigs (less than 1cm in diameter) are calculated from the tree cover percentage (UMD Tree Cover from Hansen et al., 2000) using an empirical relationship (Alleaume et al., 2003), this fuel type is a constant throughout the year.
All units are in grams of carbon/m2 * SCALEFACTOR, where SCALEFACTOR is set to 0.7 (i.e., values are reduced to 70 percent of their value). Thus, to get the image values to grams of carbon/m2, divide each pixel value by 0.7. The file naming convention is fuel_type_YY_MM_01 for the first half of the month and fuel_type_YY_MM_02 for the second half of the month. Therefore, for a given fuel type, dead grass for instance, the first file (September, 1-15, 1999) is herb_dead_99_09_01 and the last simulated step (August, 16-31, 2000) is herb_dead_00_08_02.
Additional information about the methodology and data format is found in the companion file: http://daac.ornl.gov/daacdata/safari2k/regional/fuel_load/comp/fuel_load_readme.pdf.