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4 June 2010
Attabad: spillway flow update of 08:30 this morning
There is a mass of confusing and contradictory information about the state of flow in the Attabad spillway, but the FWO data appears to be consistent at the moment. The latest data, again via Dr Sadiq, is that flow was 3700 cusecs (105 cumecs) at 08:00 local time this morning. This makes the graph look like this: This suggests that we are still seeing an incremental increase in flow. However, …
Photos of the development of the situation at Attabad
Focus have kindly provided a new set of images of the situation at Attabad with respect to the spillway. I think that these images were taken yesterday. Most importantly, here is an overview image of the spillway: It is helpful to compare this with the image of the spillway from 1st June (right hand image): It is clear that the situation has developed considerably over the last few days. The …
Attabad: a different set of discharge data
Thanks to Aftab Sadiq of the School if Civil and Environmental Engineering at NUST for passing on a revised set of spillway discharge data. This set was collected by the FWO. It is almost identical to that published here previously, with one important exception. The graph of discharge against time is as follows (correct to 17:00 yesterday, local time): The difference between this and the data that I have published …
3 June 2010
Attabad appears to have shifted to the next stage
In brief, the discharge at Attabad appears to have dramatically increased in the last few hours, as the graph below shows: I am trying to find out more information, but it appears to have shifted to a new phase of activity. Inflows and outflow may be approaching a balance. Downstream communities need to be very alert now. More as soon as I get it.
2 June 2010
Attabad – so why hasn’t it breached yet?
Several people have emailed to ask why the lake has yet to breach. Well, I would like to emphasise two things – first, that every landslide is different, so predicting the behaviour of any particular slide is effectively impossible. Second, there is a peculiarity about the spillway that appears to be delaying the breach event. Regular readers (of which there are now several thousand each day I think – thanks …
Attabad – so why hasn't it breached yet?
Several people have emailed to ask why the lake has yet to breach. Well, I would like to emphasise two things – first, that every landslide is different, so predicting the behaviour of any particular slide is effectively impossible. Second, there is a peculiarity about the spillway that appears to be delaying the breach event. Regular readers (of which there are now several thousand each day I think – thanks …
Attabad – flow continues to increase with time
The Pamir Times reports that as of lunchtime today the flow through the spillway had increased to about 850 cubic feet per second – i.e. 24 cubic metres per second, giving a discharge – time graph that looks like this: For the last 72 hours or so the increase in discharge with time appears to have been linear, which is interesting. This suggests that erosion of the saddle has yet …
1 June 2010
Attabad – continued retrogression. Close to the next stage?
The latest images from Attabad suggest that the retrogressive erosion in the channel continues to accelerate, and that this is now by far the most likely failure mechanism. A breach now looks to me to be inevitable. This image, taken this afternoon, shows how the spillway has developed: Note the people on the road for scale. Compare it with yesterday’s image: The waterfall has now smoothed out, probably because the …
Attabad – further retrogressive erosion
The latest photos from the site, taken late yesterday, show that the retrogressive erosion of the channel is continuing to develop rapidly. This image was taken at about 5 pm yesterday: The lower part of the channel has widened and, more importantly, the steep section has moved up channel considerably. Bear in mind that this image is more than 15 hours old now. The best illustration of the way that …
31 May 2010
Attabad: flow and erosion are continuing to develop
Flow through the spillway at Attabad has continued to develop during the day. However, as I suggested in my post this morning, some of the higher discharge values being quoted are without foundation. At 6 pm the discharge was about 360 cubic feet per second (10.2 cubic metres per second). Thus, the discharge graph looks like this: At the moment there appears to be little evidence from these figures that …
Dave Petley is the Vice-Chancellor of the University of Hull in the United Kingdom. His blog provides commentary and analysis of landslide events occurring worldwide, including the landslides themselves, latest research, and conferences and meetings.
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