6 May 2010
Accelerating rate of filling at the Attabad landslide in Hunza, Pakistan
Posted by Dave Petley
The rate of inflow at the Attabad landslide has now started to increase appreciably as warming and snowmelt really get underway. The graph below shows the daily rate of water increase, using data from the Focus measurements (the daily data are available on my monitoring website):
The rate of increase for the last two days with data has been 89 cm per day. At that rate the water will overtop on about 24th May, although clearly there remains considerable uncertainty around this date. It is unlikely that we have yet achieved maximum inflow rate, so the date could easily move forward again.
As of yesterday the remaining freeboard was just 17.64 metres, as this Pamir Times image from a couple of days ago shows:
Just above the boats you will see that there is a small terrace on the landslide deposit. This is the water level point at which I recommended in my report that should trigger the move to an increased alert state. We should now start to see an increase in seepage rate as the thickness of the landslide barrier decreases markedly.