In this monthly feature, we span the globe to examine Our Changing Landscape with a time series of medium-resolution PlanetScope satellite imagery. The PlanetScope constellation dates back to 2016 and collects hundreds of millions of square kilometers of 4, 5 and 8-band 3-meter imagery daily! Last month we checked out a tornado that set down in the central part of the USA, and for this August edition of Our Changing Landscape we travel to the west coast of Africa to the site of a recent heavy oil spill in The Gambia.
Click on the image above to see an animation of 3-meter natural color PlanetScope imagery collected over the location of the Mandinary oil spill in the Gambia and the surrounding region on May 25, 29, 30 and June 5, 2022. Some observations we have on the data here. First, it is obvious the surface of the river changes with each image, some of those changes are real and others are caused by changes in lighting angles. In the May 30th image, there is significant cloud cover over a key region of the photo, right be where the oil facility is located. We also see a rectangular marking in the Gambia River – perhaps this is where a boat docks to unload its oil cargo? Either way, there seems to be little disturbance in the May 29th image which would be right after the spill. In the May 30th image, you see significant sediment plumes, perhaps even oil spreading down into the Atlantic which would be to the north (top) of the images. But these plumes could also be caused by the poor band registration in the imagery which is apparent by the rainbow-affect in the clouds, that said, these plumes look accurate if the spill happened by the rectangular structure based on their shape in this image and in the other image being quite similar. Taken on their own, these images do suggest something happened by Mandinary in late May, but it is certainly not conclusive to us unless other ancillary information is considered as well. (Images Courtesy: © Planet 2022)The PlanetScope Microsat Constellation
PlanetScope is a constellation of more than 240 microsats (as of January 2022) referred to individually as Doves. Each Dove is able to collect up to 20,000 square kilometers (sq km) per day of 3-meter (m) 4-band multispectral (i.e. blue, green, red and near-infrared [NIR]) imagery; and newly launched SuperDoves collect 8-band multispectral adding in valuable red-edge spectral data. Across the constellation, PlanetScope is archiving more than 200 million sq km of medium-resolution imagery a day, making it the go to source for daily imagery over most locations. This massive archive dates back to 2016, offering the most complete and continuous record of spatial data on the planet since the start of the constellation’s ongoing launch schedule. Collecting 3-meter multispectral imagery is the equivalent of ‘high-resolution’ multispectral data imaged by a 75-centimer (cm) satellite (as this satellite would feature 75-cm panchromatic and 3-m multispectral), making PlanetScope an extremely competitively priced option at just $1.80 per sq km. With well registered images and nearly daily collections of most locations, PlanetScope is the ideal imagery source for this current-events focused series, Our Changing Landscape.
Heavy Oil Spill in Mandinary, The Gambia
Mandinary is a small town located in western Gambia on the shores of the Kunkujang Jattaya (or the Gambia River), very close to where it empties into the Atlantic Ocean. The Gambia River is home to a diverse ecosystem, including some 1,500 plant species, 80 mammalian species and 150 freshwater fish. It also supports a large oyster population which are an important food source for those living along its banks. On May 28, 2022, a large heavy-oil spill of 18,720 gallons (70,865 liters) was reported at the Gam Petroleum facility just outside of Mandinary on the banks of the Gambia River. According to a report filed on June 15th, the oil spill had spread into the Atlantic Ocean and much of it was deposited on the riverbed – clean up was underway as well. Now it is time to turn to the 3-meter PlanetScope archive to see if this ecological disaster was captured by this constellation of microsats and is visible from space.
If you would like to find out more about using 3-meter PlanetScope imagery for your academic studies, engineering projects or any landscape analysis, let us know at sales@apollomapping.com or (303) 993-3863.
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