The Rapid Decline of Lake Poopó, Bolivia
The Bolivian Government has recently placed Oruro Department under a state of natural disaster following the rapid decline of Lake Poopó. The second largest water body in Bolivia after Lake Titicaca, Poopó is a saline lake sitting at an altitude of 3,700 m, high on the Andean altipano.
Occupying 2,000 square kilometers in the 1990s, the lake has been an important resource, with nearly 50,000 inhabitants relying on it for their livelihoods. Yet the lake has been deteriorating over the past decade, with 2015 a critical year. In December, the local government’s office estimated that Lake Poopó was down to just 2% of its former water level. However it has since been declared evaporated.
The map below shows the extent of Lake Poopó every other month in the last half 2015, from June to December. The surface area was extracted by DMCii from Landsat imagery, and the rate of decline over this short, 6-month period is staggering.
What has caused the decline?
The shallow waters of Lake Poopó are vulnerable to fluctuations in precipitation, meaning it has been negatively impacted by recurrent droughts. The warming of the climate by approximately 1 degree Celsius has also contributed to increased evaporation – it is estimated that the water is now evaporating three times as fast between rains. Having suffered from these climatic changes, the lake was extremely vulnerable to the impacts of the El Niño event which arose in 2015. This phenomenon, which some consider to be the worst in a century, has accelerated Poopó’s decline.
Yet the blame cannot lay on the climate alone – human activities have also contributed to this disaster. For years water has been diverted from Poopó’s tributaries for mining and agriculture; and mining has caused other problems too. Poopó receives most of its water from the Desaguardero River, which flows from Lake Titicaca – yet the tributary has suffered from a heavy build-up of red silt, largely thought to originate from upstream mining outfits.
Although Poopó has dried up and rebounded in the past – most recently in 1997 – due to this combination of factors, it is widely considered that this is now an unlikely scenario. In the hopes of reviving the lake, the Bolivian government has asked the European Union for $140 million, part of which will contribute to dredging the Desaguadero tributaries. But critics think it may be too little too late.
The slide tool below lets you interactively examine the differences in lake extent in imagery acquired on 13th March 2015 and 5th January 2016:
What are the consequences?
Over the past two years, millions of fish are thought to have died, in addition to hundreds of birds that used to live in the wetlands, including ducks and flamingos. The lake was once a sanctuary for wildlife, in particular migrating birds; yet 75 bird species have now disappeared from the area.
The loss of the lake sees also the loss of the livelihoods of the local people who depend upon Poopó for their survival. The Bolivian government has had to provide humanitarian aid to over 3,000 people, yet this is unsustainable, and many residents see migration as their only option. So far, the lake’s decline has displaced thousands. In the small fishing village of Untavi, for example, more than half of the population have left; only the elderly remain.
In addition to the UK-DMC2 and Landsat imagery presented above, Sentinel-1 has also been documenting the loss of water from Lake Poopó this year. These Synthetic Aperture Radar (SAR) images are from March and December. In March the lake was relatively full and appears smooth and black – however the change by December is clearly evident.
Join our Twitter feed for the latest information.
Or join us on Flickr for the latest images.