Wetland Fire Scar Monitoring and Its Response to Changes of the Pantanal Wetland

Xiaodong Li,Kaishan Song,Ge Liu

doi:10.3390/s20154268

Xiaodong Li, Kaishan Song + Show 1 more

Open Access

https://doi.org/10.3390/s20154268

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Abstract

Fire is an important disturbance factor which results in the irreversible change of land surface ecosystems and leads to a new ecological status after the fire is extinguished. Spanning the period from August to September 2019, the Amazon Forest fires were an unprecedented event in terms of the scale and duration of burning, with a duration of 42 days in the Pantanal wetland. Based on the observation data of wildfire and two Sentinel-2A images separated by a 35-day interval, the objectives of this study are to use the Normalized Burn Ratio (NBR) to map the spatiotemporal change features of fire and then quantitatively measure the fire severity and the impact of fire on the Pantanal wetland. The overall accuracy and Kappa coefficient of the extracted results of wetland types reached 80.6% and 0.767, respectively, and the statistically analyzed results showed that wildfires did not radically change the wetland types of the Pantanal wetland, because the hydrological variation of the burned area was still the main change factor, with a dynamic ratio of ≤50%. Furthermore, the savanna wetland in the burned area was the wetland type which was most affected by the fire. Meanwhile, fire scars belonged to the moderate and low-severity burned areas, with a maximum burn area of 599 km2. The case enriches the research into the impact of wildfire as the main disturbance factor on the change of wetland types and provides a scientific reference for the restoration and sustainable development of global wetland ecosystems.

Highlights

“wetland fire” refers to naturally occurring wildfires, which are considered one of the most important environmental disturbing factors [1,2,3,4]
This study aims to quantitatively measure the fire’s severity and the response of wetlands to the fire by mapping wetland types as well as their changes based on open-access remote sensing data resources
Based on the premise of ensuring the continuity and integrity of the spatial distribution of fires, the Pantanal wetland’s burned and burning fields in July, August and September were manually interpreted and extracted by a mapper combined with a computer

Summary

Introduction

“wetland fire” refers to naturally occurring wildfires, which are considered one of the most important environmental disturbing factors [1,2,3,4]. With the increasingly frequent wildfires in South America during the last 15 years, grasslands and savannas present a high mortality rate. The spread of fire has greatly accelerated, leading to more open land-cover types through continuous grass layers characterized by grasslands and savannas [9]. According to the research into of the causes of fire, natural and human factors that lead to the occurrence of fire include long drought [12], rapid land-use change [13] and deforestation [14]. The slash-and-burn agriculture caused by human activities has been a new disturbance to the land-cover types in Amazon, with increasing

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