# Remote Sensing of Forest Burnt Area, Burn Severity, and Post-Fire Recovery: A Review
## 2 Materials and Methods  
### Search Methodology  
A systematic approach of a literature review from 2000 to 2021 was used in this research with a focus only on scientific peer-reviewed papers in the fields of BA, remote sensing, and forest ecosystems at the local, regional, and global levels. We selected this timeframe for two reasons. First, research in the field of applications for remote sensing and estimation of forest ecosystems and wildfires has prominently increased, especially in recent decades due to a rapidly growing number of Earth observation data sources. The progress of forest BA, BS, and post-fire recovery estimations from coarse resolution satellites to high spatial and temporal sensors was studied in the review. Second, during the last two decades, there were several comprehensive reviews from different parts of the world demonstrating a growing interest in the field of study among the professional community [39; 40; 41; 42; 43; 44].  
In order to perform the systematic review, we adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) framework [45]. The procedure of identifying, selecting, and analysing relevant articles based on PRISMA is given in Figure 1. The presented schematic diagram follows four phases: identification, screening, eligibility, and inclusion. The PRISMA 2020 checklist ([[https://www.mdpi.com/editorial_process#standards](https://www.mdpi.com/editorial_process#standards)]([https://www.mdpi.com/editorial_process#standards](https://www.mdpi.com/editorial_process#standards)), accessed on 19 September 2022) comprises a report of several sections with a title, abstract, introduction, methods, results, discussion, and other information. Each PRISMA section consists of specific formulated questions to be identified and analysed in the selected research articles.  
Following that, a representative set of keywords were defined for the initial search in the electronic databases Scopus (Elsevier) and Web of Science (Clarivate Analytics): \"remote sensing\", \"forests\", \"post-fire\", \"burnt area\", \"burn severity\". A further search was carried out in the same databases using alterations in the keywords for specific satellites (MODIS, Landsat, Sentinel, etc.). The initial attempt showed that 1140 scientific publications were identified consistently with the designated search criteria, of which 660 papers were identified through the Web of Science, and 480 were found in the Scopus database (Figure 1). During the screening phase, the articles search was refined by removing the duplicates from the two databases. Further selection was made by reading the abstracts of the papers to identify research focusing on remote sensing techniques for monitoring and estimation of post-fire forest areas. If the abstract did not clearly describe that the study was related to forest BA, we continued to review the full text to identify the objective and methodology of the article. We also excluded non-peer reviewed publications, and articles where fires have affected other ecosystems (grasslands, shrublands, agricultural lands, meadows etc.). However, this was not always possible due to the fact that, in some regional and global studies, forests were classified along with many other land cover types.  
At the eligibility phase, the full text of the remaining 605 articles were carefully reviewed based on the following criteria:  
* Remote sensing techniques are the main components of the study;
* Study should attempt temporally explicit estimation of the forest BA and BS using different datasets for the validation of mapping results;
* Paper appropriately describes the methods and/or results of the study so that they can be interpretable and replicated;
* Focus is made on the forest stands rather than other ecosystem attributes (soils, water, underground);
* Study should report detailed accuracy assessment results.