Adaptation opportunities (and challenges) with glacier melting and Glacier Lake Outburst Floods (GLOFs) in the HKH region

Transcription

1 Adaptation opportunities (and challenges) with glacier melting and Glacier Lake Outburst Floods (GLOFs) in the HKH region Jeffrey S. Kargel Department of Hydrology & Water Resources University of Arizona Tucson, AZ, USA Manuel Gonzalez Vida and Manuel Castro, University of Malaga International Expert Consultation on Mountains and Climate Change 4 April 2012, Kathmandu, Nepal Organizers: Ministry of Environment, Government of Nepal & International Centre for Integrated Mountain Development (ICIMOD)

2 Dr. David Molden this morning: Asked rhetorically, Is there a way to make glaciers lakes a resource? Stated provocatively: Energy and food security is the trillion dollar question. Dr. Madhav Karki this morning: Cited the opportunities for regional actors to take immediate with no regrets actions. Called for expert advice to mountain countries in preparation for Rio+20. Called for closure of scientific/knowledge gaps relating to assessment of vulnerability

3 Why worry about GLOFs and other glacier related mountain disasters and geomorpholoigical events? GLOFs and related events can be a natural process due to small climate and glacier fluctuations, and the impacts sometimes are restricted to wild nature. Some such events can sometimes affect small numbers of poor mountain people. GLOFs can propagate 10 s to 100 s of kilometers downstream and affect even destroy whole villages and local infrastructure. GLOFs, alpine landslides, and related events can destroy major infrastructure of regional and international scope limit development

4 A common sequence of retreat of large glaciers due to climate warming typically about 200 years 1. Period of declining ice flow, but no lakes (e.g., Gangotri Glacier, India, headwaters of the holy Ganga River) SLIGHT HAZARDS 2. Period of small pond formation. Ice exists under these ponds (e.g., Khumbu Glacier, near Mt Everest) SLIGHT HAZARDS 3. Period of runaway lake growth (e.g., Imja Glacier) RISING HAZARDS 4. Retreat into high mountain basins, with episodic renewal and emptying of lakes; lakes form ever higher in the mountains (e.g., Tam Pokhari) EXTREME AND SHIFTING HAZARD CONDITIONS

5 Stage 1: Gangotri Glacier, India Some retreat and thinning, but still few or no lakes. From Jeffrey S. Kargel, J. Graham Cogley, Gregory J. Leonard, Umesh Haritashy, and Alton Byers, 2011, Himalayan glaciers: The big picture is a montage, Proc. Nat. Acad. Sci.,

6 Mount Everest area, stages 2, 3, and 4

7 Mount Everest area, stage 2 (Ngozumpa Glacier)

8 Imja Lake development (data courtesy of Sharad Joshi, updated with Oct 2010 ASTER) From Koji Fijita et al., 2009 From Koji Fijita et al., 2009

9 Imja Lake, Nepal, October 2010 Damming ice cored end moraine Imja Lake Debris covered glacier Calving terminus of glacier

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12 Everest, Kumbu Valley, and Imja Tsho ASTER VNIR image draped over ASTER DEM ASTER 321RGB draped onto ASTER GDEM2

13 Tam Tsho Rolpa, Pokhari, Khumbu Region, Region, Nepal Nepal ASTER GDEM2 Base

14 Mount Everest area, stage 4, Tam Pokhari (small lake)

15 There is much that can be learned from the Andes. Cordillera Blanca, Peru, may serve as a glaciological/geomorphological process model of the future Himalaya. ASTER image, Palcacocha, Peru, April 2002

16 Tam Pokhari, Nepal (29 November 2005) A particularly dangerous lake for tsunamis ASTER 321 RGB (GDEM2 Base)

17 One of many unstable masses that could initiate a flood or mass movement. The slab of ice measures roughly 300m x 300m x 30m

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19 Initial Condition José Manuel González Vida Manuel Castro Dpto. Matemática Aplicada Departamento de Análisis Matemático E.T.S. Ing. Telecomunicación Universidad de Málaga Universidad de Málaga Málaga, Spain Málaga, Spain

20 Tsunami and GLOF simulation Tam Pokhari, Nepal (Spanish simulation group)

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22 Mitigation/engineering needed to reduce hazard. Possible site of small hydroelectric development? 5 MW possible (my back of envelope calculations). Would drain the lake down and reduce the hazard. Experience from nearby Dig Tsho disaster is both a caution about any development in the region, and an argument in favor of small hydel development. Can earnings from hydroelectric power development subsidize mountain studies? Same arguments don t necessarily transfer to other lakes. Case by case needed.

23 Glacier Lakes of the Khumbu Region, Nepal ASTER GDEM2 Base

24 Khumbu Region, Nepal ASTER GDEM2 Base

25 Tsho Rolpa, Nepal (01 February 2006) ASTER 321 RGB (GDEM2 Base)

26 This is why we re worried!

27 Potentially unstable masses of ice and snow

28 1. Unstable snow mass, 100 x 200 x 10 m, elev 5955 m 2. Unstable glacier ice mass 150 x 150 X 20 m, elevation 5455 m

29 Tsho Rolpa ice/snow/debris avalanche simulation t = 18 seconds

30 Tsho Rolpa ice/snow/debris avalanche simulation t = 35 seconds

31 Tsho Rolpa ice/snow/debris avalanche simulation t = 41 seconds

32 Tsho Rolpa ice/snow/debris avalanche simulation t = 1 min 7 sec

33 Climate is changing. Glaciers are changing. Glacier related mountain hazards are changing. The region is developing. Adaptation approaches must change. But one size fits all will not work! A customized applied research approach is required.