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GLOF and glacier-related hazards and risk in Tajikistan Faculty of Environmental Earth Science Tetsuya Komatsu and Teiji Watanabe Managing Climate Change in High Mountain Glacial Watersheds, Huaraz, Peru, 11-14July 2013

Teiji Watanabe: GLOF and glacier-related hazards and risk in Tajikistan

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Slides for presentation given to High Mountains Adaptation Partnership in Huaraz, Peru on 13 July 2013.

Text of Teiji Watanabe: GLOF and glacier-related hazards and risk in Tajikistan

  • GLOF and glacier-related hazards and risk in Tajikistan

    Faculty of Environmental Earth Science Tetsuya Komatsu and Teiji Watanabe

    Managing Climate Change in High Mountain Glacial Watersheds, Huaraz, Peru, 11-14July 2013

  • Previous studies on glacier hazards (Review) &

    Satellite image analysis

    (1) Geomorphological characteristics

    (2) History of glacier hazards

    Suggestions

  • Annual precipitation

    (UNEP, 2002)

    Settlements: on the younger terrace or on the alluvial fan/cone (Watanabe, 2000)

    Misau located on an alluvial cone

    L: Lenin Peak (7,143 m), I: Ismoil Somoni (7,495 m), KM: Karl Marx (6,723 m)Darjomch village (ca. 2,170 m) located on a young (35 ka?) river terrace (5 38 m higher from the river)

    Previous studies

  • Institute of Geography, USSR Academy of Sciences 6,730 glaciers7,403 km2 630 glaciers have surging history 20 surge glaciers advanced their terminus.

    Kotlyakov et al. (2010)

    Previous studies

    BOKU Universitys group: GLOF studies in the SW part of Tajik Pamir Identified 172 glacial lakes (2,500 m2) Most were formed after 1968

    Mergili and Schneider (2011), Mergili et al. (2012)

  • Case 1GLOF danger (1)

    0.01 km2

    0.04 km2

    0.06 km2

    0.05 km2

    For comparison: Imja Glacier Lake ~1 km2

  • 0.46 km2

    Case 2GLOF danger 2

    1.88 km2

    0.18 km2

  • Case 3Cascading glacial lake outburst

    1.26 km2

    0.13 km2 0.02 km2

  • 2570 m asl

    4080 m asl

    5140 m asl

    Short distance from glacier to settlement: 5 20 km

    ca. 600 m

    Simple application of early warning may not be appropriate

  • Confirmed glacier-related hazardsHazard by glacier surge (2 glacier detachments, 2 valley blocking) Hazard by GLOF (1 case)

    Ravak Glacier 20 July 1967

    200 m advanced

    Dasht Lake 7 Aug. 2002

    Bear Glacier 1963, 1973, 2011

    Didal Glacier 1974

    Blue: Surge glacier Yellow: Debris-flow hazard by surging Red: GLOF & glacial-lake hazard by surging

  • Glacier surge and GLOF: Bear Glacier NASA Earth Observatory (2011)

    Surged in 1951, 1963, 1973, 1989, 2001 and 2011 The surged terminus blocked the valley in 1963, 1973, 1989 & 2011 The dammed lake damaged infrastructure downstream.

    Base image and the termini on 2 May & 3 June: NASA Earth Observatory 2011

  • GLOF: The Dasht 2002 event Outburst of a glacial lake (4,400 m, 0.03 km2 on 7 August 2002 Reached Dasht village (2,600 m), 10.5 km downstream, in 45

    minutes. Killed 25 village people.

    PhotoSchneider and Mergili (2010)

    2 km

    Shakhdara Valley

  • ca. 200 m

    Mergili et al. (2012): GLOF occurred by collapse of

    ice-cored moraine in 2002

    Dasht lake

    Google Earth image: 31 August 2008

  • Development of Dasht Lake:

    32,000 m2 (2002) Guerrilla glacial

    lake Repeatedly appeared

    Rapidly enlarged

    Short-lived

    No surface outlet

  • Hazards assessment studies1 Schneider et al. (2010)danger evaluation of 209 villages

    2 Mergili and Schneider (2011) danger evaluation of 408 lakes

  • Glacier hazards expected

    Studied in six basins only. Glacier detachment, GLOF (debris flow?)

  • Mergili and Schneider (2011): seven classes of outburst danger

    408 lakes

    Extremely high: 0

    Very high: 6

    High: 34

    Especially dangerous: downstream of 3 lakes

    Mergili and Schneider 2011

    0.46 km2 0.33 km2

    0.15 km2

  • Considerations neededMissing area of studies Inventory of glaciers for the whole area Regular monitoring Hanging glaciers: crack Surge-type glaciers: surging Glacial lakes: development (guerrilla glacial lakes)

    Repeat appearance, rapid enlargement, & short life

    Tien Shan: 2.5 months from lake appearance to burst

    Mitigation Consideration of settlement locations and distance

    to the source area

  • Epicenter distribution, Pamir Main Pamir Thrust (northern area)

    Hindu Kush-Pamir seismic zone (SW area)

    Gordon et al. (2012)

  • SW valleys in the Tajik Pamir: Landslides

  • 20

    New monitoring

    Ultra-micro satellite,