Remote sensing applied to the study of fire in savannas: A literature review

The goal of this research is to present a bibliographic review of fire studies in savannas worldwide through remote sensing. A hybrid literature review, bibliometric and systematic approach was employed. The search string "Fire in Savanna and Remote Sensing" was used. The bibliometric analysis emphasized a quantitative approach using Bibliometrix metrics in the R software. In the systematic analysis, the reading of 57 articles from the top 10 most cited authors was highlighted, considering the H-index (Accounted for 18.5% of the total articles found). The results of the bibliometric analyses yielded 309 articles from Web of Science (WoS) and 5 from Scopus (Sco), totaling 314 non-repeated articles published between 1989 and 2022. This production refers to research from 37 countries, 134 journals, 1137 cited authors from 600 institutions. The four countries with the largest number of publications were the United States of America (23.2%), Australia (15.3%), Brazil (11.8%) and South Africa (7%). It was possible to observe that until the end of the 20th century, the number of publications remained stable and low, with a maximum of 5 articles per year, surpassing 10 articles per year from 2004 onwards. The average number of citations was high from 2002 to 2007, at over 50, decreasing from 2008. Our results are valuable for the scientific community as its reveal the most commonly used remote sensing products for savanna fire studies. Additionally, it presents current perspectives with the introduction of machine learning to Moderate Resolution Imaging Spectroradiometer (MODIS, 47% of the total) data for active fire detection and mapping of burned areas. Furthermore, the use of Light Detection and Ranging (LiDAR) for analyzing spatial patterns of fire effects on the three-dimensional vegetation structure. Studies are predominantly conducted at a local and regional scale, with an emphasis on those carried out in conservation areas and indigenous lands, possibly because savannas are better preserved in these areas. Finally, we observed a colonialism of knowledge, with a focus on Northern Hemisphere countries for savanna fire studies.