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 four and eight-band 3-meter imagery daily! In August, we looked at the monumental amount of 2023 snowmelt in California’s Sierra Nevada Mountains. This month, we’re traveling to the state of Assam, India to scope out the flooding that happened there in June 2023.

Click on the image above to see an animation of 3-meter natural color PlanetScope imagery collected over Assam, India on May 30 and June 26, 2023. First off apologies for the clouds in the June 26th image but this is the cloudy season in the region so this was by far the best we could find before the flood waters receded. The same can be said about the haze in the May 30th image. Either way, focus your attention along the river stretches in this animation and you will see significant flooding of fields. Now that you have a sense of what flooding looks like in this imagery, check out the other fields far away from the river and you see the same impacts there. Finally, zoom back out to see the entire image and watch the animation a few times, you will now easily see the extent of the flooding destruction, it is significant and heart wrenching. (Images Courtesy: © Planet 2023)

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 $2.25 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.

June 2023 Flooding in Assam, India

June 2023 brought unimaginable hardships for the people of Assaam, India as the state facesd torrential flooding. The floodwaters, triggered by the incessant rainfall of the monsoon season, wreaked havoc on the region.

Heavy rainfalls during the monsoon season are nothing new in Assam. Although it can begin as early as April, monsoon season in Assam tends to run from July into September, and often brings heavy flooding and landslides with it. Assam has been ravaged by numerous floods over the last 50 years, with floods documented in 1954, 1962, 1972,1977,1984,1988, 2002, 2004, 2012, 2016, 2019, 2020, and 2022.

This year, flooding began after heavy rains on June 14, 2023. According to Arupjuoti Saikai in his book The Unquiet River: A Biography of the Brahmaputra, Assam contains more rivers than any equal extent territory in the world. More than 40% of its area is regularly affected by flooding. According to Francis Kingdon-Ward, a British botanist, permanent glaciers, annual snowfall and rainfall are the three primary causes of yearly flooding in Assam. As we saw last month in the Sierra Nevada’s, global warming is only serving to make these precipitation events more dramatic. As temperatures get hotter, more snowmelt occurs and, coupled with heavier rains as a warmer atmosphere holds more moisture, the implications for flooding can be catastrophic.

More than 495,00 people spread across 22 separate districts in Assam were affected by the flooding. As of June 29, 7 people were reported dead and 12 districts were still impacted by the floods. According to the Flood Reporting and Information Management System (FRIMS) update, 395 villages, and an astonishing 65,759 animals were affected. 106 relief camps were set up and 5 medical assistance teams deployed to help mitigate the damages.

Landslides also accompanied the flooding in multiple districts, and many blocked roads, damaged homes, buildings, bridges, and embankments. The western areas of Bajali, Barpeta and Nalbari were among the worst affected. Along with the infrastructure damage, authorities worry that the floods could heighten the threat of disease outbreaks. Drainage backflow can mix with floodwaters, creating habitats for mosquitos and bacteria that lead to increased occurrences of insect and water-borne diseases. Contaminated drinking water also poses a health threat.

The devastation caused by flooding in areas like Assam underscores the urgent need for collective action against climate change. Only through a concerted global effort can we hope to mitigate the effects of climate change and build a more resilient future. If you feel called to donate to help assist flood victims in Assam, please visit the Humanitarian Aid International (HIA) website. You can get more information about the HIA’s plan for immediate flood relief action here. Now it is time to turn to the 3-meter PlanetScope archive to see how these June 2023 floods impacted Assam.

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.