Syria After Dark
Satellite
images of Syria taken at night capture a subtle trace left by human
civilization: lights. Apartment buildings, street lights, highways,
powerplants-- all are illuminated at night and can be seen from space.
Researchers often use these nighttime lights signatures to track
development; as cities grow, villages recieve power, and infrastructure is
built, areas emit more light. But this works both ways. As cities are
demolished, villages burned, and highways cutoff, they stop emitting
lights.
The timelapse below uses imagery from the Defense
Meteorological Satellite Program (DMSP), a joint program run by the U.S.
Department of Defense and the National Oceanographic and Atmospheric
Agency. One image is taken per year between 2005 and 2013:
Some striking trends are visible. Night-time lights increase steadily
between 2005 and 2008, a pattern that accelerates between 2009 and 2010.
This reflects the long-term urbanization of the country.
However, the most starkly visible trend is the darkness that engulfs the
country after 2011. Early fighting between government and rebel forces was
particularly destructive to infrastructure, largely due to Assad's
proclivity for the use of barrel bombs.
There are some limitations to the timelapse
above. The resolution of the (publicly available) DMSP images is relatively
coarse, and the satellite was decommissioned in 2013, two years into the
civil war. Furthermore, only one or two images is available per year.
However, a new NOAA satellite was launched in 2011 and is still up and
running. It produces images more frequently (on a monthly basis) and at a
much higher resolution than its predecessor. Below is a monthly timelapse of
nightlights spanning from April 2012 to December 2019.
The level of spatial and temporal detail in these images enables a close
look at many of the defining moments of the war.
The Battle for Aleppo
The images below were taken between 2012 and 2014. Vast
swaths of the city darken as neighbourhoods are razed by fighting.
Though this
is a trend that can be observed across the country, nowhere is the decline
in nightlights more visible than in Aleppo. Below is a comparison of
longitudinal trends in nighlights signatures between several cities:
The most
salient trend is Aleppo plummeting over the course of 2012, and becoming
steadily darker over the course of the next four years. Raqqa drops in
2012 as well, but remains in flux until 2017, when the battle to reclaim
the city pluges it into near total darkness. Damascus also experiences a
dip in 2012, but stabilizes relatively quickly. The Turkish city of
Gaziantep-- less than 100km from Aleppo and roughly 1/5th the size--
stands in stark contrast to the Syrian cities, becoming progressively
brighter over the entire period.
Another
interesting pattern here is the difference in seasonal trends in
nightlights. Under normal circumstances in this part of the world, cities
become brighter at night during the summer months. Restaurants, bars, and
markets stay open later and conduct business outdoors. Gaziantep, which
still attracts scores of tourists every year, displays pronounced
seasonality. Damascus, the most stable of the three Syrian cities, also
maintains a seasonal trend throughout the war. In contrast, both Raqqa and
Aleppo maintain extremely low and roughly constant levels of nightlights
year-round during the periods following intense fighting.
Reliable
economic data for Syria haven't been available for nearly a decade, and
assessing the country's recovery is consequently difficult. But subtle
indications of economic growth are visible above: all three Syrian cities have been on a steady upward trend since 2017, and
beginning to display seasonal variation once again.
Control over oil and gas fields
Throughout
the war, sudden massive spikes in nightlights signatures can
be observed throughout the country. In the center of the map just west
of Palmyra, some particularly large spikes occur in 2017:
These
flashes of light show gas wells being set on fire, a common form of sabotage carried out by retreating Islamic State fighters. Modified Sentinel-2 imagery of the Hayyan gas field (indicated by the green
box above) shows this in greater detail. Substituing the Red band in an RGB image with
Near Infrared (NIR) highlights thermal signatures, showing fires burning
brightly even during the day.
The large complex on the right is the Hayyan Gas Plant, which produced nearly 1/3 of Syria's electricity. The plant and its associated wells changed hands several times throughout the war, but were under Islamic State control until February 2017. In the video below, Islamic State fighters can be seen rigging the plant with explosives and destroying it on January 8th:
#ISIS Footage blowing up the #Hayan gas plant in Eastern #Homs. #Syria #Daesh #Propaganda
— JihadiThreatMonitor (@jihadi_threat) January 8, 2017
pic.twitter.com/h0PpVJ64Uh
In February, three Russian oil and gas companies (Zarubij Naft, Lukoil and Gazprom Neft) were given restoration, exploration, and production rights to the hydrocarbon deposits West of Palmyra. On January 12th, 2017, the Syrian Army's 5th Legion and Russian special forces launched a counterattack known as the "Palmyra offensive", with the aim of retaking several important hydrocarbon deposits including Hayyan.
The timing of well fires aligns closely with a detailed timeline of the campaign.The Near Infrared Sentinel-2 image below shows the layout of the Hayyan Gas Plant and the wells in the Hayyan gas field:
The Syrian Army took the Hayyan gas field on February 4th, and retreating ISIS fighters set fire to wells 1, and 3. However, ISIS managed to briefly retake the Hayyan field on February 7th, setting fire to wells 2 and 4. These moments in the Palmyra Offensive are captured in NIR signatures
Interestingly, despite the massive explosion caused by the bombing of the Hayyan Gas Plant, no prolonged thermal anomalies were detected over the area of the plant itself. The well fires, on the other hand, lasted for months. Below is an image of well fire at the Hayyan field taken from this video; based on the nearby infrastructure and date (04/02/2017) of posting, it is likely Well-3.
Fighting along the Euphrates
The banks
of the Euphrates have been cultivated since at least 8,000 BC, making this
one of the oldest continuously settled places on earth. A patchwork of
agricultural settlements can be seen lighting up the outline of the river in
2012.
In 2013, Raqqa is overrun by the Al-Nusra front and the Free Syrian Army.
This campaign ocurred with relatively little damage to infrastructure;
though the area becomes darker between 2013 and 2016, this was the result of
power outages rather than bombing. Lights can be seen slowly returning in
late 2016, before completely disappearing in 2017.
The Battle of Raqqa (known as "The Great Battle" by the
SDF), began in June 2017. As previously mentioned, nighttime lights
in Raqqa fluctuate while the city is unded ISIS control, but are
completely erased as the battle for the city reduces it to
rubble. Sentinel-2 imagery captures the extent of this destrution.
Despite
having been under ISIS control for nearly four years, the city remained
relatively intact until the 2017 offensive. As the Syrian Democratic Forces
made their advance on the ground, they were supported by U.S. airstrikes.
The grey-white patches spreading across the city show city blocks leveled by
bombing, and occasionally plumes of black smoke can be seen from recent
strikes. The agricultural fields in the bottom right corner show signs of
activity until the bombardment begins-- during the peak of the harvest
season-- after which the crops can be seen withering away. According to the
UN, 80% of the city had been left "uninhabitable" by the bombing.
Further Research
An interactive version of the nightlights
dataset can be accessed here. It also contains monthly optical imagery from the Sentinel-2 satellite,
so that trends in nightlights can be verified visually. This tool can
be used to cross-validate reports of attacks, track the destruction of a
city, monitor oilfields, or to investigate anomalies. It automatically
fetches the latest imagery, though nightlights images are released
sporradically (unlike Sentinel images, which are processed and released
weekly).
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