Tuesday, May 4, 2010

The Attabad landslide: well, that's me told then!

The Pamir Times is running an interesting story today that clearly puts me in my place!  Here it is:


“Hunza River lake would not burst, David Petley’s report is wrong”: 
Asad Zamin, DC Gilgit
Posted on May 5, 2010 by Pamir Times

PT Report

Gilgit, May 4: The report prepared by Dr. David Petley is wrong and the lake formed on Hunza River is not going to burst. Government experts have rejected any chance of lake burst.

These views were expressed by the Deputy Commissioner of Gilgit district while briefing the media about evacuation plan set up for downstream areas, at his office. He said that necessary measures are being taken because 1300 households in Hunza – Nagar and Gilgit district would be affected by the a flood that is likely to triggered by over-topping of the lake.

“There is no chance of lake outburst and we request the local populations to stay calm”, the DC, who also is the director general of district disaster management authority.

“Government of Pakistan, FOCUS Pakistan and other relevant institutions have teamed up to ensure safety of lives and property to the optimum in case of heavy flood that might be caused by over – topping”, Asad reportedly said. He also said that the 10, 000 internally displaced people will be sheltered at nine relief camps after evacuation to safer locations.

Commenting on removal of the Bailey Bridge in Danyore and the resulting isolation of Danyore and other localities he said that the Jalalabad – Danyore Road will be paved and expanded within a week to ensure supplies for Hunza – Nagar district.

The commissioner emphasized that the measures are being taken as precaution.

It is pertinent to note here that Dr. David Petley has calculated June 9 as a probable date for the spillover to take place, while also saying that the actual date might be earlier depending on volume of the water in the Hunza River. He has also said that there is a substantial risk of dam burst with the passage of time.

Three points to note.  First, my report does not say that a burst is inevitable, but that the risk is substantive.  Second, my report recommends precautionary actions.  Third, it is a brave man who says "there is no chance" about any natural system.

There are many readers here who are well-qualified to comment on the situation, so I invite you to do so.  To help I reproduce here an image from the Pamir Times yesterday showing the spillway:

3 comments:

  1. I am impressed with the confidence of pronouncing there is no risk.
    It is a bit dificult to make a prediction from a few photos, but the gradient of the spillway combined with the amount of fine grained material that will get entrained in the flow causes me to wonder if we could see a very large debris flow or debris flood develop.
    One other note. Have you or anyone else looked at past evidence of dam bursts down stream? Up stream it appears that there are old lake cut terraces on the valley slopes.

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  2. Dan, thanks for your comment. There are numerous terraces in this valley, reflecting multiple dam burst and GLOF events. Some are very large indeed - much bigger than this flood could generate. The whole landscape is littered with scars and debris from previous large rockslides and associated flood events.

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  3. Forgive me, I do not have a handle on the geography of towns and where evacuations are and are not occurring. But the way I read the article, it sounds like the Deputy Commissioner of Gilgit and others are essentially preparing for the possibility of outburst with the evacuations, road preparation, etc., but are simply calling it over-topping instead of an outburst. Perhaps they feel by refuting the danger of an "outburst" they can carry out the safety measures without public panic and at the same time maintaining some sense of national pride at not being told what to do by a foreigner. Any thoughts, Dave?

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