Kyrgyz Mountain Lakes Outbursts
Risk Assessment and Decreasing Damages from Kyrgyz Mountain Lakes Outbursts
Tech Area / Field
- ENV-MRA/Modelling and Risk Assessment/Environment
- ENV-WPC/Water Pollution and Control/Environment
- OBS-NAT/Natural Resources and Earth Sciences/Other Basic Sciences
3 Approved without Funding
Institute of Water Problem & Hydropower Engineering, Kyrgyzstan, Bishkek
- Institute of Physics, Kyrgyzstan, Bishkek
- Universita di Pisa / Dipartimento di Ingegneria Civile, Italy, Pisa\nPolish Academy of Science / Institute of Physical Chemistry, Poland, Warsaw\nUniversity of British Columbia / Institute for Resources & Environment and Land and Food Systems, Canada, BC, Vancouver\nSandia National Laboratories, USA, NM, Albuquerque\nInstitute of Water Problems, Bulgaria, Sofia
Project summaryAlmost the whole territory of Central Asia countries with the area of about 4 millions km2 and population of approximately 50 millions is the region of global ecological risk. It is connected with the following main moments:
- The most part of Water Objects (WO) is located in the mountain seismic active and dangerous regions with high risk of the natural catastrophes and cataclysms such as earthquakes, landslips, mudflows, and others, that simulate the negative structural changes in the earth surface crust. As a result some water sources may be disappeared and amounts of ground and underground water storages will be greatly depleted with the large additional pollution of water in WO.
- Under the existing deficit of the natural and artificial water sources here the hot and drought climate causes the increasing water consumption in different industrial, agricultural, and social needs.
- It is necessary to provide the WO with correct management and its safety exploitation in conditions of its specifically complex construction and the large cumulative mechanical and corrosive wear of their elements: high dams with huge water mass in artificial reservoirs; the existence of mistakes in WO projecting and older exploitation norms, developed in general more than 40 years ago in old USSR; significant drifts in rivers and other natural and artificial water arteries; non sufficient amounts and volumes of defense and nature protection works or often their total absence. In addition, the huge water masses in artificial reservoirs press on the earth crust surface and stimulate frequent and intensive earthquakes, often observed in the regions of Central Asia.
- At the mountain territories of some Central Asia countries the high power operated and non operated industrial objects are often located near natural and industrial WO. These objects are very attractive especially for so called “terrorists of new generation”, who have wish to realize global ecological catastrophes with the use of nuclear or radioactive weapon.
- All the above mentioned factors result in the high risks of realization of man-made catastrophes, including some possible elements of ecological and water terrorism. Opportunity to perform deliberate attacks of terrorists with the use of explosives may cause such catastrophes and stimulate natural calamities. It is easier to implement such attacks there due to the intersection of main lines, an available border with current centers of international terrorism, so called zones of “frozen conflicts” located in Afghanistan and Pakistan. Consequences from terrorist attacks will be followed by major human and huge material losses in these dense populated regions, and extremely negative irreversible environmental effects of global scale, including possible pollution of the World Ocean.
All these particularities are referred to Kyrgyzstan with population of 5 millions that takes a special place in Central Asia. It is situated in foothills of Tien Shan in a zone of intense development of orogenic process at abutment joint of two gigantic lithospheric plates of planetary scale: Eurasian plate from the North and Indo-Australian plate from the South. High energy of mountain relief and active seismotectonic movements determine the constant and increasingly intense evolution of the whole complex of dangerous natural phenomenon and cataclysms: earthquakes, mudslides, landslips and avalanches, mudflows and freshets, mountain lakes outbursts and underfloodings. The intense earthquakes with magnitude from 7 and higher on the Richter scale have been observed in different years.
On the territory of Kyrgyzstan there are 1923 mountain lakes with mirror areas of more than 0.1 km2, out of them about 100 lakes have mirror area of more than 1 km2; also there are several large rivers, such as the Naryn River. 95% of settlements of the Republic are situated in mountain valleys not far from river-beds, and therefore they are in dangerous zone of influence of mudflows and floods. The flows caused by the destructions of mountain lakes dams can be especially disastrous and catastrophic because of generation of huge break-through water waves with direct intense shock mechanical response on different objects and next wave transformation in space submergence zone. Numerous settlements, high-ways, power electric lines and pipe lines, agricultural grounds and pastures may be partially or totally destroyed. During last 50 years about 70 large and dangerous mountain lake outbursts have happened on the territory of Kyrgyzstan with the irreversible and tragic consequences: several hundreds people perished and the total economic damage was more than $500 millions.
Moreover, large deposits of many sorts of minerals, including uranium, gold, stibium, and quicksilver, have been mined in mountain regions of the Republic. Part of them is under exploration today. Approximately 100 millions m3 of wastage are buried in numerous tailing dumps and banks with the area of more than 1200 hectares. Radionuclids (radioactive isotopes of uranium and thorium series), salts of heavy metals (cadmium, lead, zinc, quicksilver), and toxins (cyanides, acids, silicates, nitrates, sulphates, and so on) are contained there. The mountain lakes are usually located in river water heads and their outbursts may create large hazard pollution of the water basins of the main Central Asia rivers (Syrdaria, Naryn, and others), including transboundary pollution of spacious territories of neighboring states – Kazakhstan, Uzbekistan, and Tajikistan, putting vast agricultural holding out of use. It can lead to irreversible degradation of environment on a local and regional scale, growth of economical destabilization and political tension, and putting vast agricultural holding out of use. Obviously with part of the named problems humanity is faced for the first time and today there are no analogues and ready methods which could be used to solve those problems. Therefore risk assessments, development of counter measures for prediction/prevention of the lake catastrophes and reducing their possible negative damages are very actual and important problems now. Some possible ways to solve them, described further, are the motivation for the given project implementation.
According to condition and stability of lake dams, probability of their destruction and outburst, mountain lakes subpide into two types: the lakes without danger of outburst and the lakes with danger of outburst, and there are much more of the first ones. Up to 60% of the lakes have solid nogging dams made out of strong rocks; about 20-30% of the lakes formed in deep depressions on the area of ancient moraines development (such as Arabelian ones) and therefore are steady as well. About 30% of all the lakes have unstable dams made of moraine-glacial formations or loose-aggregate loosely-coupled sediments. Such dams can be destroyed under influence of some natural and sometimes man-caused factors with subsequent outbursts of lakes with negative disastrous and often irreversible consequences for environment and population.
The mountain lakes with danger of outburst represent dynamically developing natural objects which pass several stages in their development, including the outbursting stage. To forecast outbursts of lakes and to decrease damages caused by them it is necessary to constantly monitor their states and evolution, and also to assess risks of outbursts and main parameters of their possible outburst flows. At that it is required to study in details not only condition of a lake itself and its dam, but also the surrounding mountain relief both around the lake and on the way of the break flow spreading along the underlying mountain valley. For the valley it is necessary to carry out exploration (profiling) of the territory and to determine presence of possible mudflow hotbeds; that is those sections of valley where water flow can be transformed into mudflow. In that case volume and power of break flow greatly increase. According to results of explorations a map of zone of destruction caused by break flow is made. On basis of that map system of defense from outburst flows will be organized.
At the present time a neatly developed program of determination a zone of destruction caused by break flow doesn’t exist. As a consequence it is impossible to assess risk and damage from mountain lake outbursts, and the most importantly there is no way to organize reliable system of defense from that dangerous natural phenomenon. The given project is offered with the purpose of development the program for determination the zone of destruction caused by break flow and to decrease risks and damages from their influence.
To solve the Project tasks the results of the earlier explorations of the mountain lakes and our new information on their current field investigations will be used. These investigations will include both traditional methods (engineering-geological shooting, bathymetry, hydrometry, operating observations) and modern geochemical and nuclear physical methods of analysis (such as radioisotope ones). Technical approach and methodology of works are described in details in Project Proposal.
As a result of Project implementation new data on the most dangerous mountain lakes of Kyrgyzstan will be received and risk assessment of their outbursts will be given. By the example of three chosen lakes the following scientific conceptions and investigations will be developed and described:
- criteria of detailed monitoring for determination the lake state and some of its parameters, including forecast of their further evolution;
- possible scenarios, models, and mechanisms of destructions of lake dams;
- parameters of break flow and risk of its transformation into mudflow;
- criteria of mudflow danger in mountain valleys;
- models of break flow propagation along mountain valley and piedmont plain;
- boundaries and sizes of zones of possible mechanical destructions and next submergence, caused by break flow, will be determined and marked on the special developed map;
- assessment of economical damage from lake outbursts;
- scientifically well-grounded recommendations on prevention/prediction and decreasing risks and damages, caused by mountain lake outbursts. Substantiation of possibility of risk management. Creation of defense system for population and territories.
Received results and recommendations will contribute to preservation and administration of the vast water resources of pure fresh water and in general will create certain premises for more stable and safe development not only of Kyrgyzstan, but also of the whole Central-Asian region and other mountain regions.
The leading thematic organizations of Kyrgyzstan and their well-qualified specialists – weapon scientists, geologists, geophysicists, geochemists, engineers, and technicians with large experience in the area of nuclear-physical methods of analysis, radio-chemistry, instrument-making, nuclear plant, and also specialists in data processing and modeling will be involved in Project implementation