Glacier and snow
melting in the
Himalayas and its
possible implications
International Centre for Integrated Mountain Development
Kathmandu, Nepal
Outline of presentation
• Status of glacier melting in the
Himalayas
• Possible implications for water
resources
• ICIMOD’s regional approach in
glacier monitoring
• Conclusion
Ten river basins –
the water tower of Asia
River basins of the Hindu Kush-Himalayas
Sustaining 1.3 billion people in the river basins
Impacting on food and energy production of 3b people
Himalayan glaciers are
sources of freshwater
reserves which provide
headwaters for major
river systems in Asia –
a lifeline for almost
half of humanity.
Deglaciation in the Hindu Kush-Himalayas
Glaciers in the Hindu Kush-Himalayas
Drainage basin
Mapam Yumco Lake
(Mansharovar Lake)
Number of
glaciers
Total ice
reserve
(km3)
Total area
(km2)
48
67
4.36
Ganges River System
6694
16,677
1971.49
Yarlung Zangbo River
(Bramhaputra River)
4366
6,579
600.33
Indus River
5057
8,926
850.37
Sutlej River
1900
2,861
307.93
18065
35,110
3734.48
TOTAL
Source: Map of Glacier Resources in the Himalayas, Lanzhou Institute of Glaciology and
Geocryology, Chinese Academy of Sciences, PR China, 1999
Melting of glaciers in the China Himalayas
Glacier mass balance
Himalayan glaciers are shrinking more rapidly than
elsewhere
Glacier retreat and growth of lakes in Poiqu basin,
TAR, PR China
Dyurgerov and Meier 2005
Melting of glaciers in the China Himalayas
• All the glaciers (valley) in the Himalayas have
retreated by approximately a kilometre since the Little
Ice Age [AD 1550-1850]; the Chinese Academy of
Sciences has reported that during the last 24 years
there has been a 5.5% shrinkage of China’s glaciers,
• The study predicts that if climate continues to change
at the present rate, two-thirds of China’s glaciers
would disappear by 2050, and almost all would be
gone by 2100 (China Daily, 23 September 2004).
Glacier retreat in the Bhutan Himalayas
In the Nepal Himalayas most glaciers shrank by around 8%
between 1963 and 1993 (Source: DGM Bhutan 2005)
• Raphstreng glacier retreated 42m/yr from 1968 to 2001
• Luggye glacier retreated 57m/yr from 1988 to 1998
Glacier retreat in the Nepal Himalayas
Glacial lakes studied in the Nepal Himalayas
In the Nepal Himalayas most glaciers shrank
by around 10 to 60 m/yr
Lower Barun
Imja
Tsho
Rolpa
Thulagi
Tam
Pokhari
Dig
Tsho
Snow-cover change in the Himalayas
Snow-cover change in the Himalayas
Landsat MSS image 15 Oct 1975
ASTER image of Feb 2006
Tsho Rolpa glacial lake
Ice and rock fall can cause
destructive waves
Permafrost is melting
Materials used for the inventory of
glaciers and glacial lakes
Glacial lake formation
As valley glaciers retreat, glacial lakes may form and
many are observed at elevations of around 3000 to 5000 masl
Lower Barun glacial lake
(Photos: Arun Shrestha)
Migration measures, monitoring and
early warning systems
• Reducing the volume of lake water
–
–
–
–
Controlled breaching
Construction of an outlet control structure
Pumping or siphoning the water out from the lake
Making a tunnel through the moraine dam
• Preventative measures around the lake area
• Protecting infrastructure against the destructive
forces
• Monitoring and early warning systems
• Land-use planning
AR4-HKH, projections
• Warming is likely to be well above the
global mean* in central Asia (3.70C), the
Tibetan Plateau (3.80C) and northern
Asia (4.30C) during the 21st century.
– Tibetan Plateau regional mean 0.16 and
0.320C per decade increase in annual and
winter temperatures, respectively
• Precipitation is very likely to increase in
northern Asia and the Tibetan Plateau…
AR4-HKH
The melting glaciers: attribution
• The receding and thinning of Himalayan
glaciers can be attributed primarily to global
warming.
• The relatively high population density near
these glaciers and consequent deforestation
and land use changes has also affected these
glaciers adversely .
The melting glaciers: impacts on water
• As glaciers melt, river runoff will initially increase
in winter or spring but will eventually decrease as
a result of loss of ice resources
• This is likely to be unfavourable for downstream
agriculture
• This could seriously affect half a billion people in
the Hindu-Kush-Himalaya region and a quarter
billion people in China who depend on glacial
melt for their water supplies.
The melting glaciers in the Himalayas
• Glaciers in the Himalayas are receding faster
than in any other parts of the world
• In Northwest China, 27% of the glacier area will
decline by 2050 (equivalent to an ice volume of
16,184 km3), as will 10 to 15% of the frozen soil
area
• IPCC made a forecast that if current trends
continue, 80% of Himalayan glaciers will be
gone in 30 years; recent estimates suggest this
loss in 50 years
The melting glaciers in the Himalayas
• The current trends of glacial melt suggest that
the Ganges, Indus, Brahmaputra and other
rivers across the northern Indian plain could
likely become seasonal rivers in the near
future
• Between 20 and 40% reduction of runoff per
capita is likely by the end of 21st century in the
NW provinces of China
ICIMOD’s understanding of
glacier melting
•
Glacier change is an indicator of climate change
• Regular monitoring of glaciers including mass balance is
necessary
• Monitoring of glacial lakes and adaptation and mitigation
measures for potentially dangerous glacial lakes are
required.
• The development of a dynamic and regional database on
glaciers and glacial lakes will greatly enhance the
understanding of global and regional climate trends
• GLOF events and associated hazards have transboundary
impacts
• Regional cooperation is necessary for systematic research
on snow and ice and water
For any potentially dangerous glacial lake there is
need for:
•field investigations of the lake and its surroundings,
•real time or near real time monitoring of the lake and its
environment,
•terrain analysis and field investigations in the downstream
area,
•assessment of GLOF hazard,
•simulation of GLOF scenario,
•GLOF vulnerability and risk analysis,
•mitigation measures and early warning system, and
•awareness, local responses and preparedness.
High dependence of major South Asian
countries on transboundary surface water
Per capita water availability during 2000 and
2005 (cu.m/person/year)
Country
Basin name
Population
(thousands)
Per capita water
availability* 2000
Per capita water
availability*2005
(Rec. water use: 1700
cu.m/yr)
Afghanistan
Indus,Tarim
24,926
2,986
2,610
Country
Basin
Percent of total river flow originating
outside of border
Afghanistan
Indus,
Tarim
15%
Bangladesh
GBM
91%
Bangladesh
GBM
149,664
8,809
8,090
Bhutan
GBM
0.4%
Bhutan
GBM
2,325
45,564
40,860
China
GBM, Indus,Tarim
1%
China
GBM, Indus, Tarim
1,320,892
2,259
2,140
India
GBM, Indus
1,081,229
1,880
1,750
Kazakhstan
Tarim
15,403
6,778
7,120
Kyrgyzstan
Tarim
5,208
4,182
3,950
50,101
21,898
20,870
India
GBM, Indus
34%
Kazakhstan
Tarim
31%
Kyrgyzstan
Tarim
0%
Myanmar
GBM
Myanmar
GBM
16%
Nepal
GBM
25,725
9,122
8,170
Nepal
GBM
6%
Pakistan
Indus, Tarim
157, 315
2,961
1,420
Tajikistan
Tarim
6,298
2,625
2,540
Pakistan
Indus,Tarim
76%
Tajikistan
Tarim
17%
Source: FAO’s AQUASTAT 2005
Source: FAO’s AQUASTAT 2005
*Water Availability: total actual renewable water resources
Contribution of glaciers
in water resources
River basin
Mean discharge
(m3/s)
Changes in runoff over time:
seasonal and long term
Contribution of
glacial melt in
river flow (%)
Water availability
per person
(m3/person/year)
Indus
5,553
44.8
978
Ganges
18,691
9.1
1,447
Brahmaputra
19,824
12.3
5,274
Irrawaddy
13,565
Unknown
13,089
Salween
1,494
8.8
7,876
Mekong
11,048
6.6
6,091
Yangtze
34,000
18.5
2,909
Yellow
1,365
1.3
292
Tarim
146
40.2
571
(from Jansson, Stockholm University)
(Source: Xu et al. 2007)
Climate change:
a central focus for ICIMOD
•
•
•
Integrated Water and Hazard Management
Environmental Change and Ecosystem Services
Conclusion
•
•
Sustainable Livelihoods and Poverty Reduction
•
Monitoring of cryosphere
Ecological and societal resilience
Adaptation strategies and pilots
Payments for ecosystem services
Disaster risk reduction approaches
Capacity building through knowledge management and
strengthening the Himalayan University Consortium
•
•
Need to reduce scientific uncertainty
Reduce risk from seasonal and flash
floods
Support community-based adaptation
and disaster management
Need to promote regional co-operation
in water resource management using
IWRM and IRBM approaches
Need to do policy advocacy for PES at
national and regional levels