Mapping Burned Areas in Tropical forests using MODIS data

Abstract

This paper presents a new burned area product for the tropical forests in South America and South-east Asia. The product is derived from Moderate Resolution Imaging Spectroradiometer (MODIS) multispectral surface reflectance data and Active Fire hotspots using a novel rare class detection framework that builds data-adaptive classification models for different spatial regions and land cover classes. Burned areas are reported for 9 MODIS tiles at a spatial resolution of 500 m in the study period from 2001 to 2014. The total burned area detected in the tropical forests of South America and South-east Asia during these years is 2,286,385 MODIS pixels (approximately 571 K sq. km.), which is more than three times compared to the estimates by the state-of-the art MODIS MCD64A1 (742,886 MODIS pixels). We also present validation of this burned area product using (i) manual inspection of Landsat false color composites before and after burn date, (ii) manual inspection of synchronized changes in vegetation index time series around the burn date, and (iii) comprehensive quantitative validation using MODIS-derived differenced Normalized Burn Ratio (dNBR). Our validation results indicate that the events reported in our product are indeed true burn events that are missed by the state-of-art burned area products.