Burnt Area Gallery

Next we will present you with some example cases form Europe on the detection of burnt areas using the MODIS satellite. The cases are from NASA's Earth Observatory website.

First, in the Côte d'Azur in France, there is a burnt area within the black rectangle.


Fig 5.36 - MODIS image on 28 July 2003 from NASA´s TERRA satellite.

The brownish shade east of Marseille is due to the decreased albedo resulting from the fires.


Fig 5.37 - MODIS image on 28 July 2003 from NASA´s AQUA satellite.

A slightly older example shows the aftermath of the fires that raged over Greece during the hot summer in 2003. Brownish areas depicting the burned regions can be identified all over the Peloponnesian Peninsula, as well as north of Athens. This MODIS RGB image with a 250 m spatial resolution is composed of a combination of visible and infrared bands (2.155 nm/876 nm/670 nm).


Fig 5.38 - MODIS image on 29 July 2008 from NASA´s TERRA satellite.

A shot of the island of Rhodes from the summer of 2008. The large burnt area in the middle of the island is easily recognizable.

The burnt areas show as brown in the colored image. This RGB image with a 250 m spatial resolution is composed of a combination of visible and infrared bands (2.155 nm/876 nm/670 nm).


Fig 5.39 - A map of burnt areas over Portugal between 1997 and 2004.

This map of Portugal was obtained with the AVHRR sensor onboard the NOAA satellites between 1997 and 2004, and it shows the burnt areas. Each color corresponds to a different year according to the color code in the top left corner of the image.

The summer of 2003 with its deadly heat wave and the effect it had on the wildfires in Portugal was already mentioned in the introduction of this training module. The severity of that summer's situation is clearly shown by all the brown color.

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lightbulb Did you know that fires may originate an albedo seasonal change?

Yes, scientists believe that fires in Africa may modify the natural vegetation cycle, which is usually driven by the precipitation regime related to the north-south migration of the Intertropical Convergence Zone [ITCZ].


The explanation lies in the following:


The albedo of open land is generally higher than forested land. Due to ITCZ migration, maximum albedo values are usually reached at the end of the dry season (April/May) and minimum albedo values are usually reached at the end of the wet season (October). In other words, this means that vegetation removal due to drought events originates an increase in the albedo. It is also well know that a high albedo value causes a radiative sink for the atmosphere near the surface, affecting the surface energy balance and suppressing moisture and precipitation.


On the other hand, fires originate surface darkening. In Africa, this darkening has been proved to increase the radiation absorption at the surface, excluding situations when smoke and aerosol are present in the atmosphere. Scientists believe that this increase of absorption at the surface is likely to strengthen convective activity. Therefore, it is considered that processes of albedo change due to fires should even be included in climate modelling for Africa.