An assessment of fire regimes on different vegetation types using MODIS burned area products.

Abstract

Cost-efficient satellite data has been widely used to map the spatial and temporal distribution of fires in resource scarce regions such as southern Africa. However, the accuracy of such data is often unknown, which compromises the integrity of the mapped burnt areas. In that regard, there is need to validate the accuracy of these data products if they are to be used for drawing strategies for monitoring and managing natural resources such as grasslands. This study, therefore, evaluated the mapping accuracy of the cost-free MODIS burned area satellite data products for 2013 and 2014 burning seasons in the grasslands of KwaZulu-Natal, South Africa. To validate MODIS data, we used independent reference data derived from the new generation Landsat 8 Operational Land Imager (OLI) based on the new accuracy assessment procedure promulgated. A total of 60 ground sampling sites were used in this study in conjunction with Landsat 8 data to validate MODIS burned area products. Results of this study illustrate a high level of agreement (>80% overall accuracy) between the MODIS burned area products and the independent reference data. Meanwhile, Landsat data was also validated by ground collected points yielding an accuracy of 94%. Specifically, MODIS data was validated by ground collected points yielding an accuracy of 87%. These findings suggest that MODIS burned area products (MCD45A1) are an accurate, reliable and cheap data source for mapping burnt areas at a regional scale.