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The Inevitably Preventable landslide of Badakhshan, Afghanistan The residents of the little known village of Abe Barak were stunned when a large chunk of rock and soil crashed into their homes and buried hundreds of homes within seconds on May 02, 2014. This landslide was a major human disaster this year killing at least 500 people (death toll ranges from 350-2500). A few representative photos of the failed slope are given here showing various aspects of the disaster. The first one shows a Google Earth imagery before the disaster struck the village. This landslide is classified as a “Loess Failure” which is a type of slope failure. Loess is a type of clay deposit blown by wind from a volcanic or non-volcanic source. In this case the source is the deserts and alluvial plains to the north. Loess by definition is a medium to fine grained material as wind cannot pick up larger particles. Loess by itself is stable but when it forms slopes, it becomes unstable at a certain angle. Excess water (from rainfalls or irrigation) and a minor tremor is a sure recipe for disaster. Undercutting the toe by a stream can make any slope unstable. If you look closely at the failed material, there are no large debris which is an indication that it is a loess failure. Anthropogenic activities may be partly responsible for this failure. Though the Afghans were stunned at this sight, the geological community was not. Shroder et al., 2011 has identified 34 locations of failed loess slopes in NE Afghanistan. The bedrock in Badakhshan and Takhar consist of crystalline rocks which are non-porous and on top of that are huge amounts of loess. Loess mostly consists of fine grained material, which is very porous and can be easily eroded. The excess rain and irrigation water makes it soaked and a minor tremor would cause a process called liquefaction where the entire material starts to flow like a thick paste. Was it preventable? Yes, absolutely. We have techniques to stabilize such areas should they affect human settlements, but they are at the bottom of priority list for a developing country like Afghanistan. Fixing markers on the unstable slope can indicate the villagers that the slope might be failing and they can move to safer locations. This particular event had very little to do with climate change notoriously known as global warming! As mentioned earlier, irrigation, crop patterns, heavy rains, unstable slopes and undercutting by a stream all contributed to this disaster. Unfortunately, this is not the end of the ordeal for the tragedy-struck Afghan village. Another potential threat is looming for Ab Barak. The landslide has blocked the drainage around the village and a lake has started to form as can be seen in the attached photos. This lake can burst any time as there is no active monitoring currently going on. The Afghan government needs to step up to the plate and start paying more attention to protecting its citizens from environmental disasters. @Copyright Dr. Asim Yousafzai. No part of this document may be reproduced without permission from the author. |
Dr. Asim Yousafzai
Dr. Yousafzai received his Ph.D. degree from Kent State University in 2005. He is a geoscience/geostrategy professional and has worked in the South and Central Asian regions for the past 20 years. He has published numerous articles on the natural resources, economy, politics and society of Afghanistan and Pakistan. Archives
August 2018
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