Postcard from Bishkek

The MChS, (Em-Che-Es), is the Ministry for Emergency Situations.  I wrote a short postcard about them back in January after they issued a Severe Weather Warning … well, apparently they are back in the news again – this time as a result of a series of mudflows.

One led to the city of Osh having its water supply cut off as mud had contaminated it; in another three miners were trapped in the Batken region and there have been others in the Naryn and Issyk Kul regions which caught the authorities unawares and led to criticism of them for being unprepared … and even discussions between the President and the Minister.

The issue was picked up by the blog of one of the news agencies which published the Ministry’s advice on Mudflows.

Now, when I first came here, eighteen years ago, I was warned that it was a seismically active zone (that is, prone to earthquakes), and I should make myself aware of what to do if I happen to experience one – especially as we rarely experience them back in the UK …

For the record: … that is, however, until recently when the practicing of “Fracking” was introduced when drilling for gas and oil and the process is being blamed in some quarters for what s perceived as a substantial increase in the number and severity of earthquakes,  Fracking is a technique where water is mixed with sand and chemicals, and then  injected at high pressure into a wellbore to create small fractures, (typically less than 1mm).  The pressure is then removed from the well, then small grains of proppant (sand or aluminium oxide) hold these fractures open once the rock achieves equilibrium. Apparently, the technique is commonly  in wells searching for or extracting gas and oil.

As far as I am aware – there is no fracking in Kyrgyzstan … but if anyone knows otherwise – please tell me.

So I looked up some advice and even prepared handouts with a summary of that guidance, to distribute if anyone asked … you can find it in this postcard.

Since then I have learned to be aware of the possibility of avalanches, (which can block some of the main roads and periodically cut off remote communities – even Naryn), and landslides, (which seem to occur most frequently in the South after wet weather and have been known to take several lives – even burying small communities).

Once again, these natural hazards are not unknown in the UK – but are extremely rare and so, as with earthquakes, I decided it was better to do some research and prepare myself – just in case – and, likewise, I produced some notes summarizing what I had learned.  (You can the those summaries on the postcards about avalanches and landslides.)

That might sound pretty frightening but, in fact, they don’t happen all that often and, although there are risks, there are steps that can help to minimize the threat.  Some of those relate to the location of buildings and so forth whilst others concern the actions to be taken during the course of an event if someone is unfortunate enough to be caught up in them.

In fact, a review for The United Nations International Strategy for Disaster Reduction, (UNISDR), suggests that the risks of fatalities from “floods” (that’s all forms of flooding – not just mudflows) is relatively low, (0.04 deaths per year per million of the population), although the resulting disruption  effect a much greater, disproportionate, percentage of the population.

 

So – mudflows … the name can be a bit misleading because, although it generally refers to a rapid flow of “mud”, (soil and water mixed together as viscous fluid), down a streambed, there are also debris flows which can occur especially in high mountain regions – in which the “debris” being carried by the flow can included rocks, plants and even trees.

In some of the narrow gorges, for example, the “wave” of the flow can, according to the MChS, be as tall as a five storey building”, travelling at the speed of an express train, (that is, for example, 80 kph – or 50 mph), then it is easy to understand that the mass of water has sufficient power to uproot and carry away old trees and even boulders weighing several tons.

The areas most likely to be at risk of a dangerous mudslide include: Areas where the vegetation has been denuded, for example as the result of wildfires or human modification such as where slopes have been altered for the construction of buildings and roads; Areas where landslides have occurred before; Steep slopes and areas at the bottom of slopes or canyons; Channels along a stream or river; Areas where surface runoff is directed.

According to a report for the UNDP in 2011, “dozens” of mudflows occur throughout the piedmont, foothills and mountainous regions of Central Asia -and in some areas they can occur as frequently as every three years. In Kyrgyzstan, it notes, ,ost of the country is exposed to some extent with over a thousand settlements possibly threatened and around 850 flash flood and mudflows events were registered between 1990 and 2008 with another 92 in the first nine months of 2009.

It also pointed out that as one of the areas most affected is in the Ferghana valley, the events have the possibility of being a international problem, as flood waters originating in the mountain rivers of Kyrgyzstan (and Tajikistan) threaten the foothill and lowland areas of Uzbekistan in a densely populated area.

 

According to the MChS, here in Kyrgyzstan, the most powerful mudflows occur, usually, in June … when the warmth of the summer sun starts melting the glaciers high in the mountains and millions of tons of water are accumulated “lakes” in the moraines – the rock debris that is deposited as part of the glaciation process.  If a moraine lake high in the mountains, (say above 3000 meters asl) bursts its banks, the resulting stream rushes downhill, constantly expanding and increasing in power.

Indeed, we have seen such events recently in the Ala Archa Gorge where a lake high in the mountains burst its banks and swept down the valley – washing away several of the dachas (summer cottages) near the entrance of the National Park – although the power of the flow was dissipated as it left the gorge and entered the Chui plain and so it never reached Bishkek.  This year, it was feared that there may be a repeat of the situation and the lakes were subject to special monitoring … fortunately, this time, they were well behaved and stayed where they were.

There are other factors than can contribute to a mudflow: heavy rainfall, a reservoir overflowing, a landslide or earthquake.

The risk of severe mudflows may be increased in the future as a result of Global Warming which is predicted to create more intense rainfall; warming in winter resulting in rainfall replacing snowfall, which is likely in turn to extend the period when mudflows may occur;  high rates of evaporation leading to greater aridity of the soil which means that the top soil layer will be more easily washed away, and may lead to less vegetation which could exacerbate erosion; and the possibility of greater amounts of moraine being exposed as a result of retreating glaciers.

On their website, the MChS offers advice for all sorts of situations … including advice about mudflows.  It’s only available in Russian, so I have paraphrased it here – including altering the order in which two or three of the points appear.  The page also has some photos – but as they are copyright, I haven’t copied them here.

Tags: For_the_Record