Landsat Remote Sensing Data

The Landsat project captures a wide variety of heterogeneous data about the surface of the Earth approximately every 16 days. Most of its satellites, including Landsat 7 and 8, are placed in sun-synchronous and near-polar orbits to accomplish this. Landsat imagery has been used to document the deforestation of the rain forests which has been crucial to understanding why it occurs. The imagery will prove beneficial in reforestation efforts brought on by wildfires in Oklahoma, Kansas, and the Okefenokee National Wildlife Refuge. Mapping glacier loss additionally helps us monitor climate change in remote areas where statistical anomalies defy global trends. The Landsat project offers a very high-resolution view of Earth’s environment.

Deforested areas (light green and pink) of the Amazon rain forest captured by Landsat between November 13th, 1986 (left) and October 30th, 2016 (“Monitoring Deforestation in the Amazon,” 2017).

One application of the remote sensing data collected by the Landsat project is to monitor the deforestation of the Amazon rain forest. The imagery collected by Landsat documents the deforestation that has been occurring over the past several decades. It is used to determine the reason for the deforestation which is primarily agricultural farming and cattle grazing. Deforestation anywhere is particularly problematic because plants and trees convert CO2 into carbohydrates which produce oxygen as a byproduct during photosynthesis (“The Carbon Cycle and Earth’s Climate,” n.d.). Destruction of these forests means that there’s less plants offsetting global carbon emissions in the atmosphere from industrialized nations as these areas become industrialized themselves. This is why world leaders have been taking steps with things like the Paris accord to set international agreements for climate emission reductions and mitigation. Interestingly, the agreements are considered so important that even countries like North Korea have praised them (Finnegan, 2017). Landsat tells a similar story of forest loss in Cambodia where a surge in land concessions has contributed to an accelerated rate of deforestation. The Okomu Forest has also been subject to the same industrial demands of large-scale rubber and oil palm plantations.

Another tangible application of the data is the monitoring of drought and wildfire conditions. Landsat 8’s data will be used in planning the reforestation of the Okefenokee National Wildlife Refuge after a wildfire that was ignited by lightning is contained. Infrared radiation band measurements of vegetation by Landsat will also assist with wildfires in Kansas and Oklahoma where 780,000 acres of farm and ranch land have been scorched. Understanding where these wildfires spread is necessary when assessing the damage caused to both wildlife ecosystems and human property. A lack of geological data would preclude strategizing containment efforts and planning evacuation routes.

The growth of Pio XI Glacier in the Southern Patagonia Icefield between October 4th, 1986 (left) and October 22nd, 2016 (“As Glaciers Worldwide Are Retreating, One Defies the Trend,” 2017).

What I felt was the most important application of the data was the monitoring of changing climates and ecosystems. It’s important to consider that humans have only been around for a fraction of the Earth’s existence and that the planet wasn’t always as habitable to biological life as it is today. The Landsat imagery has captured a wide array of changes to our planet’s climate over the decades which could have a profound impact on its habitability. Certain anomalies have been recorded such as the growth of the Pio XI Glacier that is defying global glacier trends of decreasing ice mass. However, supplemental data may be necessary, like the depth of the lakes it flows into, in order to determine why the glacier shows abnormal growth. This glacier may be important in understanding why other glaciers are melting. When glaciers melt they release trapped methane and other greenhouse gases that may contribute to global warming. Methane is a more potent greenhouse gas than carbon dioxide by as much as 86 times (Vaidyanathan, 2015). It is believed that as global warming progresses, more glaciers will melt, and the process becomes cyclical.

In conclusion, the Landsat project collects data that is essential to a lot of our most critical science research. The imagery collected tells us many stories about the changes occurring in our global environment from the deforestation of rain forests to wildfires, natural disasters, and the growth and shrinking of glaciers. It is for these reasons that I believe the USGS’s Landsat project has contributed positively to many applications of the scientific community.

References

As Glaciers Worldwide Are Retreating, One Defies the Trend [Online image]. (2017, May 18). Retrieved June 08, 2017, from https://remotesensing.usgs.gov/gallery/gallery.php?cat=3#582

Finnegan, C. (2017, June 7). North Korea blasts Trump as ‘silly,’ ‘ignorant’ over Paris Accord withdrawal. Retrieved June 08, 2017, from http://abcnews.go.com/International/north-korea-blasts-trump-silly-ignorant-paris-accord/story?id=47898345

Monitoring Deforestation in the Amazon [Online image]. (2017, May 18). Retrieved June 08, 2017, from https://remotesensing.usgs.gov/gallery/gallery.php?cat=3#710

The Carbon Cycle and Earth’s Climate. (n.d.). Retrieved June 08, 2017, from http://www.columbia.edu/~vjd1/carbon.htm

Vaidyanathan, G. (2015, December 22). How Bad of a Greenhouse Gas Is Methane? Retrieved June 08, 2017, from https://www.scientificamerican.com/article/how-bad-of-a-greenhouse-gas-is-methane/

Leave a Reply