Gralhas fire, February 2017 Sarraquinhos, Gralhas, Solveira
The fire started on 22 February 2017 in Gralhas, Portugal, and satellites saw it burning for 2 days. Copernicus mapped a burnt perimeter of 134 hectares from satellite imagery, spread across 3 municipalities.
This entry is most likely a pasture burn or a prescribed winter burn in northern Portugal, not a wildfire. In these hills scrub is burnt to renew grazing, and this fire is not in the ICNF register of rural fires. This is our assumption, based on the time of year and the lack of an official record; it is not confirmed. That is why it is left out of the wildfire rankings.
The power measured by the satellite is low (24.2 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
- Burnt area
- 134ha
- Copernicus perimeter
- Duration
- 2days
- 22 Feb 2017 – 23 Feb 2017
- Municipalities hit
- 3
- freguesias
- Started on
- 22 Feb
- 2017
- Heat detections
- 3
- in a single hotspot: 24 MW
- Danger at start
- 1
- Very low · FWI index
- Energy released
- 62MW
- sum of detected power
Where it burned
How it evolved, day by day
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 3 days without rain (1 mm or more) when it started. Rain came after the fire: 1.7 mm on 27 Feb.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
Sarraquinhos 300 inhabitants · 2.3 km from the town77 ha2.3 %
-
35 ha reached on 23 Feb1.6 %
-
Solveira 150 inhabitants · 2.7 km from the town22 ha reached on 23 Feb1.8 %
Burnt area inside each municipality, from crossing the official perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.
What burned
- Other natural land59 %
- Scrub and transitional woodland41 %
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
The weather day by day
ECMWF ERA5 reanalysis at the fire location, the standard reference for past weather, and the Canadian Fire Weather Index (the same system Copernicus uses), computed by WorldFires from that data. Days after the fire run until the first rain.
Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 22 Feb | 15.4 °C | 37 % | 25 km/h | 0.0 mm | Very low 1 |
| 23 Feb | 14.8 °C | 43 % | 29 km/h | 0.0 mm | Very low 2 |
| 24 Feb after | 13.6 °C | 52 % | 26 km/h | 0.0 mm | Very low 2 |
| 25 Feb after | 14.2 °C | 50 % | 23 km/h | 0.0 mm | Very low 2 |
| 26 Feb after | 10.0 °C | 70 % | 31 km/h | 0.0 mm | Very low 2 |
| 27 Feb after | 7.9 °C | 73 % | 57 km/h | 1.7 mm | Very low 1 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.
Detections table · 3Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the Gralhas fire last?
- Copernicus dates it between 22 February 2017 and 23 February 2017: 2 days between the first and last image with fire.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 134 hectares (1.3 km²). Official national figures may differ.
- Which municipalities burned?
- The fire entered 3 municipalities: Sarraquinhos (77 ha, 2.3 %); Gralhas (35 ha, 1.6 %); Solveira (22 ha, 1.8 %).
- Did the fire reach a town?
- The closest fire to a town centre came within 2.3 km of Sarraquinhos. That is the distance to the perimeter or nearest hotspot; it does not mean it entered the houses.
- What was the weather like?
- During the fire the temperature reached 15.4 °C, humidity dropped to 37 % and gusts hit 29 km/h. The fire danger index (FWI) reached 2, class Very low.
- Where does this data come from?
- From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Portugal (geoBoundaries). It is not an official report.
Where to verify it
A satellite detection is not an official report. Final figures and the fire’s status are published by each country’s emergency service.
Emergency number: 112
- ICNF · Instituto da Conservação da Natureza e das Florestas ↗
- ANEPC · Proteção Civil ↗
- Fogos.pt (ocorrências em tempo real) ↗
Satellite cross-check
Does something look wrong on this page?
This page is built from satellite data and official records, and it sometimes gets things wrong: the wrong dates, the wrong town, two fires merged into one, or something that was not a wildfire at all. If you know this fire first-hand (you live nearby, saw it, fought it or reported on it), tell us what really happened and we will check it.
Report an error
Where this data comes from
The perimeter and land cover come from the Copernicus European Forest Fire Information System (EFFIS), measured on MODIS and Sentinel-2 imagery and published under CC BY 4.0. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Municipal boundaries come from geoBoundaries ADM3 (CC0 1.0 Universal (CC0 1.0) Public Domain Dedication). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from each country’s official figure.