Eyes on Earth Episode 5 – Declassified Data at EROS
There’s a lot more than Landsat in the EROS Archive. In this episode of Eyes on Earth, we hear from a professor who’s mined satellite data collected during once-classified military missions to peer into the history of land use in Eastern Europe during the height of the Cold War.
YOUNG: Hello everyone. Welcome to this episode of Eyes on Earth, a podcast that focuses on our ever changing planet and on the people from across the United States and the world who use remote sensing to help us monitor the health and well-being of our earth. Iím your host, Steve Young. Todayís guest is Dr. Volker Radeloff, a professor in the Department of Forest and Wildlife Ecology at the University of Wisconsin in Madison. Welcome Dr. Radeloff.
RADELOFF: Thank you. Thank you for having me.
YOUNG: So, you have used declassified images from the archive at EROS in your work. How so?
RADELOFF: Yes. That was work that we did in eastern Europe. The declassed data is data that was taken by US, essentially spy satellites, rockets that took cameras into space to take photos on the ground in the late ë60ís, and throughout the 1970ís, and ë80ís. So, that data is available now. It is black and white photography, so it is a little bit different but it is very high resolution. Itís about 2 meter, 6 feet resolution so we can see a lot of detail and where houses are, where farm fields are, the land use pattern in that era. Itís really exciting because it predates what we can get from the Landsat record by a decade or two. And that is important because when the Landsat imagery kicks into play it was already the end of the Soviet Union and things had started to change in the mid ë80ís or so. Whereas, with the 1970ís data we captured the peak of the Soviet era.
YOUNG: So when you get that information, what do you do with it?
RADELOFF: So, we have done one study in Romania. In Romania, there was a lot of logging after World War II because Romania was on the side of Nazi Germany in World War II and had to pay reparation to the Soviet Union. Romania is a poor country so the way it paid was either with oil or with timber. And they harvested entire watersheds. So they would harvest 50,000 acres at a time. And with the Corona data, this harvest happened in the 1950ís-1960ís, we can see those harvests. We cannot see them in the Landsat record because it is too late. So, we were able to make an analysis of all of Romania looking at those harvests which were far more extensive than anything since. But in the Corona data, the data is so detailed that in addition to the clear cuts we could see the rafts of the logs on the rivers that they used to transport them on. Itís fun. Iíve worked with satellite data for a long time. The level of detail we can see in the 1960ís in many places exceeds what we can see now.
YOUNG: Do you have any idea what we were interested in when we were taking those images?
RADELOFF: Yes, the Corona Program has been credited with keeping the Cold War cold. And the goal was to count the assets the Russian military has especially in the intercontinental ballistic missiles. And it was very successful in doing that. And thanks to that, previous estimates of Soviet capabilities that were much much higher, were kind of put into place. So the Soviets had plenty of rockets but not as many as we feared before we could count them.
YOUNG: You were studying long term land degradation in the Caucasus. What does that mean? What are you interested in?
RADELOFF: Yes. For now, we are working in the Caucasus Mountains again with Corona data. And the Caucasus Mountains are between Turkey, which is a NATO member, and Soviet Russia, so an area of high strategic importance. We got a lot, a lot of imagery for the Caucasus mountains for the 1970ís and we are interested to see how the land use has changed from those Soviet Era times then with the collapse of the Soviet Union with a lot of wars in the Caucasus ëtil today. Things changed pretty drastically. The Soviet Union broke down country borders but after the collapse, Georgia, Armenia, and Azerbaijan became their own countries and that changed where they could sell their products and who they would trade with and so forth. That also changed how the forests were used and how the grasslands were used. On the forests side there used to be quite a bit of a logging industry there for the manufacturing of furniture. That ceased. But on the other hand, people needed fuel wood because they no longer had access to cheap heating materials otherwise. So that caused degradation of the forests of the Caucasus because people went out and cut trees here and there. And that is something where we can use Landsat data to monitor it, but itís a little bit different than the monitoring of deforestation because the logging of trees here and there causes a degradation of the forest but not quite as drastic as a signal then when we remove the entire forest. The other thing happened in the grasslands, that some areas were over grazed and so at that point there was high soil erosion and so forth. One example is that in the past, Georgian Shepherds would every year migrate with their herds to the northern Caucasus, to the Russian side, and had done so for over 1,000 years or so, and have winter grazing areas there. After the collapse of the Soviet Union, those migrations were interrupted. Now, they are grazing in Georgia and that changes where the grasslands are being degraded.
YOUNG: I think you made reference to the fact that youíve studied Chernobyl?
RADELOFF: Yes, So, what we studied in general was the land use change after the collapse of the Soviet Union throughout eastern Europe. And Chernobyl is a particularly fascinating place because in 1986 the reactor exploded and they created what they called the exclusion zone. So, within 50 kilometers everybody had to leave. They were forcefully resettled. So, that is an extreme example of agricultural abandonment because no one is living there anymore. In 1991, the Soviet Union collapses. So, now, we can look at what happens after that. Due to the socio-economic shock, which was severe, within one year the GDP of the Soviet Union/Russia was cut in half. And the interesting thing is that the effect of the socio-economic shock on land abandonment in the Ukraine was just as severe as the explosion of the reactor. The rates of abandonment were the same outside of the exclusion zone after 1991. It was that extreme. We have areas for the north in Russia near Malinsk where 80% of all farm fields have been abandoned and forests are re-growing. Now, that is a rate of abandonment that is very, very rare. In the US, we also had abandonment in the northeast when people gave up farming in New Hampshire and moved to South Dakota, or so, but it was over a much longer period. In eastern Europe it happened very rapidly. Chernobyl gives us a nice reference point because it was such an extreme event. But the socio-economic shock in many regions had the same effect without the explosion of a nuclear reactor.
YOUNG: How did you become aware of Corona images?
RADELOFF: I had heard of the Corona images for a while and it was declassified initially already in the 1990ís. And there were great documentaries showing how the Corona capsules would be sent down from space with parachutes that airplanes would catch over the Pacific and so forth. I was just fascinated by that. But, then I thought for a while just given my work at eastern Europe, that having imagery from the 60ís would be really important. And we started a project. We had a full-bred scholar who came from Romania, who had a lot of experience georectifying imagery from drones. He got the ìCorona bugî and he started working with a software thatís called ìStructure from Motionî, that can handle data from platforms that are not so stable. And Corona is like that, and could rectify this with 40-meter accuracy, half a Landsat pixel or so. And that, all of a sudden, then opened the opportunity to do larger area mapping.
YOUNG: Were you aware that we had this Corona imagery available here at EROS? How did you become aware of that?
RADELOFF: Well, I knew we could order it through the national archives and then when we started ordering more, I learned that the actual imagery is at EROS, and all the scanning is done at EROS. So, at some of the meetings I go to where we talk about land cover, land use/change, some of the contractors were there and they recognized my name and said, ìYou are one of our bigger users.î So, we started chatting. This morning I had a chance actually to see the scanning operations and go down in the archives. Itís very impressive to see.
YOUNG: I was going to ask you what you thought of that. You saw not only the scanning but the film archive.
RADELOFF: Itís immense. And It is so neatly organized and everything. Clearly, the films are in good hands here. Itís such a rich data source, that my secret hope is that at some point the USGS will do with the Corona data what was done with the Landsat data and scan the entire archive and make it freely available. And, I think that would change how the community is using it. So, right now, even within the Landsat science team or with the remote sensing community people are aware of Corona. But, there is a barrier to use. And, lowering that barrier, I think, would be great.
YOUNG: Weíve been talking to Dr. Volker Radeloff about his work in the Caucasus and Chernobyl. Itís been a fascinating conversation, Dr. Radeloff. Thank you for joining us.
RADELOFF: Thank you so much for having me. This was great.
YOUNG: We hope you come back to the next episode of Eyes on Earth. This is a podcast that is a product of the US Geological Survey Department of the Interior. Thanks for joining us.