Fire regimes have shown significant deviations from historical patterns, raising concerns about the resilience of natural habitats. The Pantanal, the world's largest tropical wetland, epitomizes a critical biodiversity hotspot under threat. The catastrophic fire that ravaged the Pantanal in 2020 raised doubts and uncertainties about the region's ecological future. Moreover, severe fire events were recorded in 2019, 2021, and most recently, in the summer of 2024, underscoring the persistent and escalating threat to the ecosystem.

In this study, we explore the interplay between fire regimes and wetland refill patterns in the Pantanal. Our investigation spans a five-year period from August 2018 to July 2023 and integrates a diverse array of datasets, including fire incidences, precipitation patterns, land cover classifications, and inundation dynamics. Central to our study is the incorporation of a new inundation data: the UC Berkeley Random Walk Algorithm WaterMask from CYGNSS (Berkeley-RWAWC). This dataset offers enhanced depiction of monthly wetland inundation extent through clouds and plant canopies, and we observe reduced wet season refilling following mega fires from previous fire seasons in 2019, 2020 and 2021. Further, we developed a multi-object tracking algorithm to analyze fire patterns with the MODIS Burned Area product (MCD64A1 v061). Combining Density-Based Spatial Clustering of Applications with Noise (DBSCAN) method and the Hungarian method, the algorithm pinpoints initial fire ignition locations and track their developments. This work enables us to distinguish between fires likely of anthropogenic origin, such as those caused by agricultural practices, and those occurring naturally, such as lightning-induced fires. Understanding the origins of these fires is crucial for determining whether they are primarily caused by climate variability, such as extreme temperatures and drought conditions, or if these climatic factors act to intensify the fires.

This work explores the mechanisms governing the interactions between fire behavior and wetland refilling, provides a nuanced understanding of the ecological processes at play. Our study aims to contribute to the broader discourse on wetland resilience by offering new insights into the factors driving fire behavior and wetland dynamics.