Fire scar mapping in a southern African savanna

Abstract

Multitemporal principal components analyses (PCAs) of pre- and post-burn Landsat Thematic Mapper images were used to map fire scars in Madikwe Game Reserve (MGR), South Africa. Prior to MGR's inception in 1991, when the land was used for extensive cattle ranching, overgrazing and fire suppression lead to bush encroachment. Fire is currently being used to control bush encroachment. Bands 3, 4, 5, 7 and a NDVI band from both pre- and post-burn images were included in both the 1994 and 1996 PCAs. Fire scars comprised the fourth principal component (PC4) in both years. Fire intensities were classified via a density slice of the PC4 data within fire scars. In 1994, fires covered 31% of MGR and in 1996, 56%. In both years, fires were more frequent and intense on soils with lower bush densities (and therefore higher grass fuel loads) than on soils with higher bush densities. These fire scar maps are aiding ongoing fire management efforts in MGR.