Glaciers as Indicators
Figure 1: Estimated average annual streamfl ow, in million
Figure 2 : Example of glacier area/altitude hypsometry and
cubic metres per year, from a) glacier melt, b) 4000-6000 m
location of E0
altitudinal belt, and c) basin total, into glacierised gauged
max
for the Dudh Kosi Basin
basins in the Nepal Himalaya. Catchment basins are:
1. Bheri, 2. Kali Gandaki, 3. Budhi Gandaki, 4. Marsyangdi,
5. Trisuli, 6. Dudh Kosi, 7. Tama Kosi, 8, Likkhu, 9 Tamor.
Estimated 0
0
C o
Estimated 0 C
isotherm altitude
isotherm altitude = Approximately 5400 m
= Approximately 5400 m
Comparative streamfl ow volumes, mcm
Area (sq.km)
Annual Volume, mcm
Elevation (m)
Basin Compute melt below 5400 m using a regional mass balance gradient, estimated
4-6 km
range 0.6 to 1.4 m/100 m. Current pilot study uses 1.4 m/100 m for probable
maximum runoff volume from ice melt
Glacier Melt
of land above sea level (hypsometry). Nine basins in References
Nepal met these criteria. The glaciers of these nine
Alford, D; Armstrong, RL; Racoviteanu, A (2009) Glacier retreat
basins contain approximately 80% of the total glacier
in the Nepal Himalaya: An assessment of the role of glaciers
surface area of the Nepal Himalaya. Figure 1 shows in the hydrologic regime of the Nepal Himalaya. Washington
the estimated relative contributions of (1) glacier melt,
DC: The World Bank South Asia Sustainable Development
(2) runoff from all sources in the 4000-6000 m altitude
(SASDN) Offi ce, Environment and Water Resources Unit
belt, and (3) the total annual catchment basin streamfl ow Armstrong, RL (1989) ‘Mass balance history of Blue Glacier,
volume from these nine basins. The glacier contribution
Washington, USA’. In Oerlemans, J (ed), Glacier fl uctuations
to basin stream fl ow varies from approximately 20% in
and climate change, p 417. Dordrecht: Kluwer Academic
Publishers
the Budhi Gandaki Basin to approximately 2% in the
Likhu Khola Basin, averaging approximately 10%. This
Eriksson, M; Xu J; Shrestha AB; Vaidya, RA; Nepal, S;
volume represents approximately 4% of the total mean
Sandström, K (2009) The changing Himalayas: Impact of
climate change on water resources and livelihoods in the
annual estimated volume of 200,000 million cubic
greater Himalayas. Kathmandu: ICIMOD
metres for the rivers of Nepal. Under current climate
conditions, our preliminary study indicates that the
Haefeli, R (1962) ‘The ablation gradient and the retreat of
a glacier tongue’. Association of Hydrological Sciences 58:
glaciers of Nepal experience no melt over 50% of their
49 - 59
surface area at any time of the year (Figure 2). This is in
sharp contrast to lower elevation glaciers of the world
Kaser, G; Osmaston, HA (2002) Tropical glaciers.
Cambridge: Cambridge University Press
that do melt over their entire surface during the summer
months, often resulting in signifi cant mass loss.
Konz, M; Uhlenbrook, S; Braun, L; Demuth, S; Shrestha, A;
(2006) ‘Process-oriented runoff simulation from a glacierized
An analysis of the glaciers and hydrological regime of
Himalayan head watershed’. Geoph Research Abstr 8(04247)
the mountain catchments of the entire greater Himalayas
Wagnon, P; Kumar, R; Arnaud, Y; Linda, A; Sharma, P;
will be required to assess regional variations in the role Vincent, C; Pottakal, J; Berthier, E; Ramanathan, A; Hassnain,
of glaciers in stream fl ow production in the western
SI; Chevalier, P (2007) ‘Four years of mass balance on
Himalayas, Hindu Kush, and Karakoram. It is assumed,
Chhota Shigri Glacier, Himachal Pradesh, India, a new
benchmark glacier in the western Himalaya’. J Glaciol
based primarily on anecdotal evidence, that the
53(183): 603 - 611
percentage contribution of glacier ice melt to regional
stream fl ow will increase in an east to west direction
WGMS (2008) Fluctuations of Glaciers 2000-2005,
Haeberli, W; Zemp, M; Kääb, A; Paul, F; Hoelzle, M (eds)
across the Himalayas. However, it should be noted that
Zurich: World Glacier Monitoring Service (ICSU(FAGS)/
both the precipitation and the total stream fl ow decrease
IUGG(IACS)/UNEP/UNESCO/WMO)
when moving from the relatively wet monsoon climate
of the east to the dry, more continental, climate of the
western Himalayas.
16