Burned Area, Recurrence of Fires and Permanence of Burnt Scars in Selected Areas of the Brazilian Cerrado Using Tm-landsat Imagery

A study was conducted in two selected areas of the Brazilian cerrado using Landsat imagery during a five years period (1996-2000), to address the following estimation issues: (1) burnt area using statistical sample techniques; (2) burnt scars permanence; and (3) recurrence of biomass burning. Regarding the burnt area estimates, a decrease of approximately 60% was observed during the period and was consistent in both study areas. It was also observed that the physiognomies most affected (wooded savannah and shrub savannah) remained the same throughout the period considered. A method was developed to allow a quantitative assessment to be made for the mean time of permanence of the burnt scars. The results indicated that there exists a large annual variation that also depends on the type of physiognomy affected. Regarding the recurrence (reincidence period), the most common pattern was characterized by the occurrence of only two burns in the period, spaced by two years time.