Potentially dangerous glacial lakes in Kyrgyzstan

Research
group
of
Hydrology
Research group of Hydrology
Potentially dangerous glacial lakes in Kyrgyzstan
http://hydro.natur.cuni.cz
http://hydro.natur.cuni.cz
Research overview of 2004-2015
Bohumir Jansky1, Sergey Yerokhin2, Miroslav Sobr1, Zbynek Engel1, Michal Cerny3, Kristyna Falatkova1, Jan Kocum1, and Vojtech Benes4
(1) Faculty of Science, Charles University in Prague, Czech Republic, (2) Kyrgyz State Agency for Geology, Bishkek, Kyrgyzstan, (3) Geomin, Jihlava, Czech republic, (4) G Impuls, Prague, Czech republic
 Territory
 Major sites
Kyrgyz republic
Petrova
Area: 198,500 km²
Population: 5.3 mil.
Population density: 25 people/km²
Capital: Bishkek
Mt ranges: Tien Shan, Pamir, Alay
Mean altitude: 2,750 m asl
Highest peak: Pik Pobedy 7,439 m asl
Glacier area: 8,169 km²
Retreating glacier Petrova (40-60 m/yr) causes lake area and volume growth.
Now the lake has area over 4 km² and volume of 70 mil. m³. It is dammed
by a large complex frontal moraine in which there are over 30 thermokarst
lakes. ERT showed existence of buried ice inside the dam. Lowering of lake
level to reduce pressure on the dam was proposed and conducted.
Areas of interest
•
•
Jansky, B., Engel, Z., Sobr, M., Benes, V., Spacek, K., Yerokhin, S. (2009). The evolution of Petrov lake and moraine
dam rupture risk (Tien-Shan, Kyrgyzstan). Natural hazards, 50(1), 83-96.
Engel, Z., Sobr, M., Yerokhin, S. A. (2012). Changes of Petrov glacier and its proglacial lake in the Akshiirak massif,
central Tien Shan, since 1977. Journal of Glaciology, 58(208), 388-398.
1. Kyrgyz range – lakes in valleys Sokuluk,
Ala Archa, Kegety, Issyk-Ata, Chon Kemin,
Alamedin, Lake Chayish
2. Kungey Ala-Too – lakes in valley Chok-Tal
3. Ak Shiirak – Lake Petrova
4. Terskey Ala-Too – lakes in valleys Chong
Kyzyl-Su, Lake Zyndan
5. Talas range – lakes in valley Cherkanak
6. Babash Ata – Lake Kutman-Kul
7. Alay range – Lakes Tegermach
Adygine
Research station bulit in 2008 is at altitude of 3,600 m asl.
It has its own energetic system and can hold up to 8
researchers at once. It is in operation from May to October.
Glacial complex Adygine is a convenient site with it‘s
accesible glacier, moraines of different age and more than
20 lakes of different origin. Lakes form a 3-level cascade:
the lowest one and those in contact with glacier terminus
are considered potentially dangerous.
Total of 32 lakes mostly of glacial origin
situated in 14 different valleys were studied
at various levels.
 Methods
•
Hydrology: stream discharge, lake water level monitoring,
bathymetric measurements, physical parameters of water
Climatology: basic meteorological parameters measurement
Geodesy: demarcation of lake shoreline, glacier terminus,
valley and channel profiles
Geomorphology: analysis of lake‘s watershed
Geophysics: gravimetry, GPR, geoelectric methods
Engineering-geology, hydrogeology
Helicopter monitoring flights
•
Jansky, B., Sobr, M., Yerokhin, S. (2006). Typology of high mountain lakes of Kyrgyzstan
with regard to the risk of their rupture. Limnological Review,6,135-140.
Falatkova, K., Sobr, M., Kocum, J., Jansky, B. (2014). Hydrological regime of Adygine Lake,
Tien Shan, Kyrgyzstan. Geografie, 119(4), 320-341.
There are several recorded outbursts per year in Kyrgyzstan, those
in distant regions without settlement may occur unnoticed. To study
the site right after an outburst is very useful for proper understanding
of possible outburst mechanisms. Lakes where repeated outburst
occured should be monitored to learn circumstances preceeding the
event. Various sensors are tested to serve as part of early warning system.
Lake Cherkanak
subsurface
drainage channel
Lake Zyndan
after drainage
Koltor
Channel below
the lake
Lake‘s dam composed of a moraine and landslides is about
300 m long and 250 m wide, outflow is subsurfacial.
Resistivity tomography showed dam seepage (down
middle). Dam overflow occurs during fast glacier melting or
after heavy rainfall. This lead to development of erosional
gully on airy side of the dam. Upper edge of the gully was
stabilized to stop its progression to dam crest.
•
Contact to authors:
Charles University in Prague, Faculty of Science, Prague, Czech Republic
Albertov 6, Prague 2, 128 43 Czech Republic
[email protected], [email protected], [email protected]
This poster is available at: http://hydro.natur.cuni.cz/EGU
 Lake outbursts
Jansky, B., Sobr, M., Engel, Z. (2010). Outburst flood hazard: case studies from the TienShan Mountains, Kyrgyzstan. Limnologica, 40(4), 358-364.
Lake Testor had repeated outbursts, last event was in July 2012.
The lake 16 days before outburst (left) – the usually empty depression
was partly filled. Despite lake‘s small volume the flood transformed into
a debris flow with estimated max discharge of 300 m³/s. Ala Archa
channel (downstream of Testor) 4 hous after the lake drained (right).
The flood was recorded in 40 km distant capital.
erosional gully: 3D model
Acknowledgements:
Created with support of Czech development cooperation projects 194/07-09/MŽP/B (RP/27/2004) „Monitoring of high mountain glacial lakes and protection of the population
against catastrophic impacts of floods from moraine lake outbursts“, and RP/9/2007: “Analysis of the risk of failure of alpine lake dams and the mitigation of the consequent
impacts; Kyrgyz Republic”, NATO CLG project “Glacier hazards in Kyrgyzstan: implications for resource development and water security in Central Asia” and GA UK project no. 619112
“Risk analysis of glacial outburst lakes in Adygine area (Tien Shan Mts, Kyrgyzstan)”. Our thanks belongs to Tomáš Hrdinka, Václav Mašek who helped with field measurements.
www. natur.cuni.cz