Determining Fire Dates and Locating Ignition Points With Satellite Data

Akli Benali,Renata Pinto,José Pereira,Ana Russo,Owen Price,Nikos Koutsias,Ana Sá

doi:10.3390/rs8040326

Akli Benali, Renata Pinto + Show 5 more

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https://doi.org/10.3390/rs8040326

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Abstract

Each wildfire has its own “history”, burns under specific conditions and leads to unique environmental impacts. Information on where and when it has started and its duration is important to improve understanding on the dynamics of individual wildfires. This information is typically included in fire databases that are known to have: (i) multiple error sources; (ii) limited spatial coverage and/or time span, and; (iii) often unknown accuracy and uncertainty. Satellite data have a large potential to reduce such limitations. We used active fire data from the MODerate Resolution Imaging Spectroradiometer (MODIS) to estimate fire start/end dates and ignition location(s) for large wildfires that occurred in Alaska, Portugal, Greece, California and southeastern Australia. We assessed the agreement between satellite-derived estimates and data from fire databases, and determined the associated uncertainty. Fire dates and ignition location(s) were estimated for circa 76% of the total burnt area extent for the five study regions. The ability to estimate fire dates and ignitions from satellite data increased with fire size. The agreement between reported and estimated fire dates was very good for start dates (Model efficiency index, MEF = 0.91) and reasonable for end dates (MEF = 0.73). The spatio-temporal agreement between reported and satellite-derived wildfire ignitions showed temporal lags and distances within 12 h and 2 km, respectively. Uncertainties associated with ignition estimates were generally larger than the disagreements with data reported in fire databases. Our results show how satellite data can contribute to improve information regarding dates and ignitions of large wildfires. This contribution can be particularly relevant in regions with scarce fire information, while in well-documented areas it can be used to complement, potentially detect, and correct inconsistencies in existing fire databases. Using data from other existing and/or upcoming satellites should significantly contribute to reduce errors and uncertainties in satellite-derived fire dates and ignitions, as well as improve coverage of small fires.

Highlights

Wildfires play a major role in ecosystem dynamics and pose as an important threat to lives, human and natural resources of fire-prone regions
If the assignment was not possible, After constraining the data in space and time, we found some ambiguous active fire detections that could belong to more than one fire perimeter
The ability to estimate fire dates from satellite imagery increased with fire size (Figure 4)

Summary

Introduction

Wildfires play a major role in ecosystem dynamics and pose as an important threat to lives, human and natural resources of fire-prone regions. At the global and regional levels, the causes. At the landscape level, each wildfire is a distinct event with its own “history”, ignited and burning under specific fuel and weather conditions, leading to unique social and ecological impacts [2,3]. Characterizing individual wildfires is relevant to identify associated causes [5,6], to understand the factors controlling fire occurrence [7,8], to estimate fire risk [9], characterize fire regime [10], to understand the complex interactions between fire spread and its main drivers [11], to estimate carbon emissions [12] and assess fire-related impacts [13]. Improving the quality and quantity of the information regarding individual wildfires has important implications for fire suppression and management, and for improvement of prevention policies [5,7]

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