7 February 2010

The Attabad landslide – caught between the devil and the deep blue sea

Posted by Dave Petley

News from the landslide site at Attabad is increasingly grim, despite the ongoing work to create a spillway. The Pamir Times has an excellent article here outlining the impact of the rapidly expanding lake. This lake is now 11 km long and has inundated 460,000 square metres of land, 11 houses and 3.5 km of the Karakoram highway.

However, the spillway that is under construction is a further 79 m above the current lake level, meaning that at its maximum point the lake is expected to inundate 7.55 million square metres of land, including 187 houses, the homes of 1,736 people, and 25 km of the Karakoram Highway. The next problem is expected to occur at the bridge between Shashkat and Gulmit, which the lake has recently reached (see the image below, from the Pamir Times):

To give you an idea of the size of the lake – this Google Earth image shows the location of the landslide dam and the bridge (click on the image for a better view in a new window:

The next crisis will arise when the bridge is inundated as at this point the communities along the Karakoram Highway between the bridge and the dam will be isolated. The Pamir Times article suggests that there are 3000 people in this area, which is probably correct based on the images:

All of this emphasises the magnitude of the problems in this area, which are receiving scant attention from the outside world. When the water reaches the top of the dam it will have flooded a very large area. If the dam remains intact, a huge reconstruction programme will be needed for the Karakoram Highway, and a huge number of people will be displaced. This image shows the location of Hussaini village, which is where the article estimates that the head of the lake will be when the spillway is reached:

On the other hand, if the dam is eroded away then an immense flood will travel down the Hunza River, endangering a very number of people. The 1856 flood caused damage down as far as Attock, which is 360 km away as the crow flies! Unfortunately, the possibility of a sudden collapse of the dam cannot be ruled out as the lake fills.