So what to do now? Well, it is clear that there is a huge social cost to the current situation, which probably cannot continue for much longer. It is also surely clear that the current monitoring team cannot maintain the current level of activity for long given their living conditions. So here is my suggestion for a way forward. Please note this is not advice, and should not be treated as such, but rather it is a starting point for discussion.
1. NDMA sets up a detailed, integrated data collection system based upon, but enhancing, the current Focus activities. This should include the following measurements at 6 hour interval:, with the first measurement each day being taken at dawn
- The flow rate in the spillway
- The seepage rate
- The lake level
- Landslide activity
- The inflow rate
- Temperature
- Seismic activity
3. This is backed up with real time monitoring, preferably automatic, of inflow, landslide / rockfall activity at strategic points along the lake, and outflow, feeding a warning system. A command centre is established that would operate the alarm system should landslide flow rate increase. Boat crews and people in the red zone are trained as to what they should do if the alarm sounds.
4. The expert group meets at dusk each day to plan for the next day.
5. Alongside this a study is implemented immediately of management options for the spillway. This study should be undertaken properly, with international input, and will be made openly available when complete. A timetable is placed on the production of this report, and on the decisions that will be made on the basis of it.
6. All of this is backed up with a transparent communication strategy that explains the risks and benefits of the current situation, and of the various options.
This would seem to me to be the best balance between maintaining safety and allowing people to start to rebuild their lives. Of course this strategy will increase the risk that people face from the dam - but there are real risks associated with their displaced state too that we need to start to reduce. However, I must emphasise that to do this safely NDMA must use expert advice - this cannot be done any other way.
Excellent thoughts on what to do next.
ReplyDeletePamir Times has reported that the local people might resort to self-help to widen the spillway. I take that as a measure of their perfectly understandable level of frustration.
However sending large numbers of people to widen the spillway by digging will expose them to the hazards of unstable slopes above that are continuously giving way. People would very likely be lost or injured.
What else could be done?
1. A cofferdam would allow the underlying slabs to be exposed, drilled and blasted. But in the interim the lake level will raise considerably and the question of deploying an adequate number of drilling rigs to do the job quickly before more villages are submerged and the cofferdam is challenged by rapidly increasing water level would have to be addressed. With the flow at the current rate, I seriously doubt this is a viable option. That said, it's always possible another landslide could block the spillway and produce the same results and hazards as a cofferdam.
2. Bridging the channel with gantries (provided the difficult problem of support on unstable slopes could be solved) and drilling from above again raises the question of getting sufficient equipment there. The amount of equipment supplied to dig the spillway testifies eloquently to the low capabilities available.
3. Given the paucity of viable alternatives, bombing the streambed slabs with precision guided munitions seems about all that's left. I would start at the top, observe results for a few days, then work the lake level down through the slabs a bit at a time. Once the last slab goes, retrogressive erosion could drain the remaining lake in very little time.
George
This makes is sound like the lake actually adds economic value: "A well planned lake drainage work can create lots of jobs (even if for a short time) to benefit the affected families - to say the least. We must look at the opportunities that this situation provides us, and how we can turn our misfortunes into fortunes."
ReplyDeleteOnce the lake is drained there is nothing to sell. I've heard someone suggest auto theft is a good thing, as it creates lots of jobs: First those who steal gain, and then the insurance company pays for a new car. The workers who build the new car win. Everyone wins, right? Oh, did I forget about the insurance company who had to pay?
There is a possible mechanism for accelerating the cut through of the dam yet maintaining a level of control.
ReplyDelete1. Cautious use of explosives to remove controling features.
2. Cautious use of new "landslides" to reduce the flow when the situation looks to be on the verge of getting out of hand.
There are some rather large rocks perched above the current spillway that might be shifted into the channel at strategic moments to help control the flow.
Requires considerable preparation because you don't want to be caught one landslide short.
Just a concept for operations.
Thoughts??
Waiting out the Summer high flows would require Winter quality accommodation for all the displaced people. Lowering the lake soon would allow the people to rebuild in time for the Winter. But the decision properly belongs to those who live there. Many downstream are resistant to lowering the dam, but their problem is that it might suddenly fail at any time, even though that could be years from now.
ReplyDeleteGeorge
http://tribune.com.pk/story/21588/authorities-relieved-as-outflow-equals-inflow/
ReplyDeleteGabster... "It's not possible to make a second spillway, while the existing one is at the low point..."
ReplyDeleteIt is possible, if found feasible after expert investigations and professional analyses. Yes, I fully agree that the scale of work is 'massive' to say the least. However, organizing a massive earthwork (after the feasibility is established) is not impossible. I have the first hand experience of earthworks of even greater proportions (several hundred million cubic meters in a single opertation). So just by looking at the scale is not a valid reason to conclude that its 'impossible'. Just to quote from Nelson Mandela "Every thing looks impossible until it is done".
I am rather surprized that many are wanting the dam to burst (or to make it burst...). That would create the big flood wave of destruction. The strategy at this point should be to somehow "break" the possible flood peak down to a non-destructible level.
tropical... "did I forget about ... who had to pay?
ReplyDeleteIf you think government of Pakistan is too poor to finance it, please think again. The whole opeartion will cost less than a couple of Presidential Visits to Europe and N. America. A country where even the lesser executives are using Gulfstream and Citaion type business jets should not worry too much about the bill... it will be a small one when measured against the wealth we have :)
I agree with this: "However, if somehow we can manage a gradual drainage of lake and avoid a devastating flood peak, the displaced people would return to thier houses still intact and their lands still useable."
ReplyDeleteThe point I was trying to make was not about the potential damage of the lake, but rather that the "job creation" theory was not based on sound economic theory.
Ultimately this situation is tragic. First minimize the loss of human life and personal injury. Beyond that, let's consider the best option, rather than try and sell a solution based on "jobs creation." That's a play toward desperation.
Has any one, NDMA or Focus, made an estimate of the total volume of water stored in the lake for the current lake level? Is there a lake-level to lake-volume relationship derived for this site?
ReplyDeleteDivalent... 'local "volunteers" trying to take matters into their own hands '
ReplyDeleteThis underpins the importance of involving locals in the management of the this crisis.
If we let them feel involved (rather than isolated and dictated) in various tasks and activities within the overall framework of a carefully thoughtout strategy, these motivated individuals could be an asset.
There is no point in allowing the lake to grow if it offers no solution instead growing hazards. How about this?
ReplyDelete1. Get the boulders out by blowing them with anti tank guided missiles. These weapons can be airlifted and then fired from a safe distance at the boulders. Being hollow charge, these warheads will cause little collateral damage and cause no land slides. However, due to their size, we may need scores of warheads. Then wait for a few days to determine if the flow was really being stopped by boulders or not. If it was, the spillway will deepen and widen also eroding the saddle.
2. If not then go for the saddle.Use the same missiles at regular intervals to deepen the saddle, a few meters below the lake level. The rush of water would cause more erosion and the lake may start emptying. This process will have to be repeated when the inflow outflow become the same, till such time the whole lake is emptied.
If this is not done, we live in a permanent hazard.
I am doubtful about anti-tank missiles as they are designed to melt through metal armor plating after which a modest explosion is enough to do in the crew, but
ReplyDeletenot destroy the tank completely as many armed forces like the opportunity to rehabilitate the tank and reuse it. There is a large above water slab where an ATM could be tested to see if it's up to the job but I remain doubtful about ATMs as something heavier seems indicated.
Perhaps the locals might be able to bypass the controlling underwater slab as the surrounding ground at the upper part of the spillway is less steep and not as deeply piled up as in the saddle. If the upper slab is bypassed, further downcutting may happen, providing other underlying slabs do not interfere.
Ideally it would be determined just what lies below the spillway all the way down to the original streambed. I suspect it would be reasonably safe to blast down one slab level at a time so long as there's another massive slab immediately underneath. We have seen that so far nature has not been able to move these slabs or erode around them -- at least until the next earthquake when they might all let go all at once tomorrow or several years from now.
George
A few days ago I read a very interesting comment from Colonel(Retd) Kaiser Hameed Khan, who had proposed using water jets ( Giant Water Cannons) like the ones used in Hydraulic mining to widen the spillway and wash away the Debris which is choking the spillway.Increased water flow would then expedite the draining of the lake. If this is a feasible option, it should not be as dangerous or risky as the explosive option, and also a cheaper option for our country.Though I have no experience of anti Tank Missiles I do not thnk missiles do any damage to rocks otherwise bunkers would not be defended with earth and boulders.I have heard of Dam Burster Bombs but never of Anti Tank Missiles bursting dams.
ReplyDeleteAny way I wish someone conveys these comments to NDMA who seem to be completely stunned with the behavior of the DAM.
Saleha Raza