Glaciers and Glacial Lakes under Changing
Climate in Pakistan
The Himalayas, Karakoram and Hindukush lofty mountain ranges meet each
other in Pakistan hosting more than 5000 glaciers in Pakistani geographical
limits which feed snow/ice melt water to the Indus River System together with
summer monsoon. Due to global warming, frozen water resources have been losing
their reserves at an unprecedented rate, not only, reducing the ice mass but
increasing the number and extent of glacial lakes. Glacial Lake Outburst Floods
(GLOFs) are the devastating mountain hazards which have started occurring with
increased frequency during the recent years. An alarming increasing temperature
trend in northern parts of Pakistan during the last decade which surpassed all
the past records has enhanced the snow/ice melt rate and given rise to lake
formation process some of which are potentially dangerous for outburst. Due to
increase in temperature, the snowline has shifted upward causing migration of
biodiversity and lower elevation glaciers have started melting faster. Snow
used to occur now in late winter and disappears in early summer, hence,
reducing the residency period to complete metamorphic processes for conversion
into ice. Ponding of melt water underneath and around the terminal moraine need
continuous monitoring to understand their supraglacial behavior and to assess
the potential danger of outburst on scientific basis for development of an
early warning mechanism. An initiative of The Mountain Institute (TMI) in
collaboration of ICIMOD toward Global Glacial Lake Partnership is a step
forward to manage such lakes to mitigate the potential losses due to their
outburst.
Introduction
Pakistan is located in
South Asia between 24°-37°N latitude and 66°-77°E. It hosts the triple point
(junction) of three world famous mountain rages Himalayas, Karakoram and
Hindukush in its north. There are more than 5000 glaciers feeding the Indus
from 10 sub-basins through different tributaries ranging from few tens of
meters to more than 70 km long. According to glacier inventory developed by
ICIMOD in 2005 with the help of RS/GIS techniques, over this glaciated domain,
there are about 2500 glacial lakes formed due to glacier melt waters and 52 of
them were declared potentially dangerous for Glacial Lake Outburst Flood
(GLOF). The GLOF events are catastrophic as huge loads of debris and mud flows
downstream sweeping the infrastructure, houses and crop-lands resulting in
scores of life losses if it happens without any alert signal. For mountain
population, GLOF is the greatest hazard which is being reinforced by climate
change in terms of frequency and vulnerability. Booni Gole Glacier located near
Chitral in Hindukush mountain range generated outburst flood in July 2010
triggered by monsoon downpour and caused huge erosive damage
to agricultural
land and human settlements along the flow channel. It used to store water under
the terminus of the glacier and produce surge either by accelerated melting of
snow/ice or by intense rainfall. Due to steep slope downstream, the carried
loads of mud, debris including heavy boulders gain momentum and cause heavy
loss
es to land, settlements and infrastructure. Passu lake outburst had also
followed the similar mechanism in the past with the frequency of outburst at an
irregular interval of 2 to 5 years. The scene of its damages is quite visible
travelling from Karakoram Highway as Passu village is located along that
highway. There is an increasing tendency of formation of new lakes and
expansion of existing ones near the glaciers of the Himalayas and Hindukush as
confirmed by the temporal comparison of satellite imagaries. Recently UNDP has
taken an initiative to study two glacial lakes in Chitral and Gilgit by in-situ
observations and remote sensing tools in association with local public and
private organizations concerned with glacier monitoring and research.
Hopefully, a warning system will be developed to save the lives of the people
most likely exposed to that hazard. Experience of Bhutan may be replicated with
certain modifications in accordance with organizational and social set up.
Climate
Change
Although there are both
natural and anthropogenic reasons of climate change but latter is the most
dominant with an ever increasing trend since the industrial revolution of
1940s. Population growth in developing countries, which makes about 70% of the
comity of nations, has been too high putting an increased pressure on fixed
natural resources and the compensation of increased demand for food and shelter
through better socio-economic conditions. Increasing population and changing
life style under economic transformation raised the level of anthropogenic
contribution to climate change many folds as compared to always existing
natural ones. Economic development at the cost of environmental degradation
played very important role in producing drastic rise in global warming and
hence changing the climate over the
global and regional scales. Glaciers and
icy surfaces are the most sensitive indicators of global warming which have
shown their immediate response in terms of mass balance and contribution of
melt water to the sea level rise. Accelerated melting of glaciers generates
voluminous water accumulating in deeper pans giving rise to the formation of
glacial lakes which continue to increase their size and hence water content.
When the water accumulated in such lakes exceeds certain limit and develops
enormous pressure on the retaining walls of the lakes, the weakest bank
surrenders to outburst and whole of the volume of water rush down slope
carrying debris and boulders. Such outburst floods are sudden in nature
therefore inflict huge losses to downstream population, land and
infrastructure. The reasons of climate change can be categorized as natural andanthropogenic while latter is dominating the former one.
Global warming due to
human activities has been affecting all aspects of life posing serious
challenges to the availability and utilization of natural resources. Rise in
temperature registered during the first decade of 21st century has been two
times higher than it was anticipated. According to World Meteorological
Organization (WMO, 2011) statement on status of climate, the first decade
(2001-2010) is the warmest decade recorded over the globe and 2010 ranked as
the warmest year (+0.53°C) followed by 2005 (+0.52°C) and 1998 (0.52°C).
Sixteen warmest years of the globe occurred during the last two decades.
Snowline Shift
Snowline is the extent of
down slope elevations upto which snow used to occur during the winter season.
They are the regions where air temperatures drop below zero for an extended
time period. A research study conducted by Rasul, et al., 2006 pointed out that
snowline has risen up slope by about a 1 km during the last 25 years. They have
also stated that the frequency, intensity as well duration of heat waves (High
temperatures persisting for 10 consecutive days) have increased considerably in
early summer season which triggered snow/ice melt floods downstream. They
carried out isothermic analysis on pentad basis considering the march of 30C
isotherm. Its upward movement with the passage of time marked the warming of
low elevation thermal regime along the northern mountains. To confirm the
research results, a survey was conducted interviewing the elders of the region
who confirmed that in the past they used to receive heavy snowfalls in winter
and doors of their houses used to remain shut for several days but they
3 Glaciers and Glacial
Lakes under Changing Climate in Pakistan.
Glacier Melting
Most of the world
glaciers are subjected to depletion with a few exceptions (IPCC 2007) posing
serious challenges to water security. Schroder et al., 2007 found that the loss
of significant glaciers in Afghanistan and Pakistan may become more serious progressively
unless warming generates greater marine evaporation that augments
precipitation. The global retreat of glaciers is striking and interaction of
atmosphere-cryosphere approach is appropriate to study the dynamic behaviour of
glacial fluctuations (Kaser, 2001; Wagnon et al., 2001). Temperature analysis
revealed that snowline has shifted about one kilometer higher than its location
25 years before resulting into upward migration of animals and plants species
(Rasul, 2006). The effects of global warming in mountain areas are visibly
manifested by shrinking of mountain glaciers and reduced snow cover duration
(Barry, 2002). However, Hewitt (1998) reported the widespread expansion of
large glaciers in the central Karakoram, accompanied by an exceptional number
of glacier surges. Rasul et al., 2008 reported that the frequency and intensity
of heat waves have significantly increased over the southern slopes of HKH
along with an unprecedented increasing trend of annual mean temperatures over
this heavily glacierized region. There are contrasting results from scientists
about this region. The main reasons of this controversy include insufficient
in-situ measurements, lack of data sharing and projection of small scale study
over the entire region. However, all the scientists agree upon that low
elevation glaciers are losing their ice mass at a faster rate and high
elevation glaciers are comparatively stable or melting at a slow rate.
Most of the glaciers in
Pakistan’s geographic limits are debris covered and melting rate differs
according to the thickness and type of debris in addition to the other factors
such as their aspect, elevation etc. Pakistan Meteorological Department in
collaboration with several international research groups have been recording
in-situ meteorological data and glacier characteristics by high altitude
Automatic Weather Stations (3000-5000amsl) installed over the glaciers and
through field measurements since 2006. At present 10 large glaciers are being
studied in Karakoram and 2 in Hindukush Range. However, the extensive research
is focused on two major glaciers Baltoro (heavily debris covered) and Passu
(relatively clear). There are 3 AWS installed over the Baltoro Glacier and two
at Passu Glacier at an elevation ranging from 3000 to 5000 masl. The results of
ablation experiments conducted on Baltoro.
During the field visits, it was noticed that huge amount of water was
held under the ice bulk near the terminus (tongue) of many glaciers especially
in case of Booni and Passu glaciers which used to cause mysterious outbursts in
the past. As such large volume of water ever increasing was not visible,
therefore caused serious damages downstream to human lives, settlements as well
as infrastructure.
Recently a lake on
Hinarchi Glacier grew rapidly in surface area as well as depth. Field teams of
PMD snapped the likely formation of lake in 2008 along the moraine. It was
surprising that a small pond (about 100 m2) of water expanded into a big lake
(1100 m2) when snapped the same site after three years in 2011. The samples
collected from the terminal region of the Hinarchi Glacier in 2009 were
analysed and results show a significant deposit of black carbon along with
other contents of debris. Source of carbon may be the burning of wood in
villages which deposit on icy surface due to low level inversion in the valley.
CLIMATE CHANGE AND VARIABILITY IN
MOUNTAIN REGIONS OF PAKISTAN
IMPLICATIONS FOR WATER AND
AGRICULTURE
Abstract:
This paper analyzes climate variability in the mountain areas of Pakistan
covering
region and on the bases of these analyses, discusses implications for
water and
agriculture for the country. Trend analyses of the historical data for
the period
1971-2000 show that winter season temperatures have increased in both
submountain
and high mountain region during the past 30 years. Relatively higher
increase in maximum winter temperatures was observed, whereas minimum
temperatures during winter showed a slight decline. These results
suggest that
days have become warmer whereas nights have become cooler during the
winter
season in the high mountain areas. Monsoon temperatures (particularly
maximum
temperatures) have also increased in both the regions. More
interestingly,
maximum temperatures in the transitional periods “October-November” and
“April-May” particularly in the high-mountain areas are at a rising
trend. All
these changes and seasonal variations have important implications for
water
resources and agriculture in the mountain areas in particular and for
Pakistan in
general.
The results indicate that the maximum temperatures have increased all around
the
year particularly in the high mountain region during the last 30 years.
Winter
temperatures have increased in both sub-mountain and high-mountain
regions
during this period. Rainfall has also increased in both regions. The
paper
concludes that the increasing trends in temperature in the high mountain
areas
may have some positive impact on crop area and yields. However, these
rising
temperature trends may increase the melting of glaciers and snow, reduce
snow
accumulation during winter and enhance the overall de-glaciations
process and
therefore could well endanger the country’s sustained sources of fresh
water from
glaciers and snow melting. Detailed analysis is however recommended to
assess
the impact of climatic variability and change on water and agriculture in the
mountain areas.
Mountains of Pakistan:
Geographical Location
Pakistan is located
within the latitudinal and longitudinal extensions of 24 to
37°N and 61 to 76°E
respectively. The country has Arabian Sea to the south
and high mountains in the
north. Northern mountains comprise parts of the
western Himalayan and
Karakoram ranges with a small part of the Hindukush
range. Pakistan is the
only place where these three great mountain ranges meet.
Besides the northern
mountains, there are western highlands separated by
Kabul river from the
mountainous north and consist of series of dry and lower
hills. The eastern half
of the country is mostly dominated by the flood plains of
the river Indus and its
tributaries viz. Jhelum, Chenab, Ravi and Sutlej rivers.
Parts of Balochistan and
Sindh provinces constitute deserts (Sheikh and
Manzoor, 2004).
Implications for Water Resources:
Glaciers and snow in the
high mountain regions of Himalayas and Hindu Kush
feed the Pakistan’s
Western and Eastern rivers, and which largely forms the
country’s 70% of the
fresh water resources. The glaciers of our region are however
under severe threat due
to rising temperatures associated with climate change.
Study by Rees and Collins
(2004) suggests that glaciers in Himalayas are receding
faster than any part in
the world and if the present rate continues, the likelihood of
their disappearing by the
year 2035 could be very high.
Our analysis in this
paper points towards rising temperature trends in the high
mountain areas which
could have serious implications for our fresh water
resources. Particularly,
the increasing trends in maximum temperature during all
the melting of snow and
glacier in these areas. More importantly, increases in
temperatures in the winter
season might have negatively affected snow
accumulation in these
high mountain areas, and increasing maximum temperatures
during April-May and in
the subsequent periods might have accelerated the
depletion of snow and
glaciers in these areas. This phenomenon of the melting of
snow and glaciers needs a
thorough investigation and is beyond the scope of this
study. But a point that
is made here is that temperatures in the high-mountain areas
are rising which could
well enhance the de-glaciation processes in these areas and
could endanger the
country’s sustained sources of fresh water resources.
A rising trend in
rainfall both in the high and sub-mountain areas might bring some
beneficial effects in the
mountain area. However, being highly fragile and
numerous anthropogenic
factors are already causing land degradation in the
mountain areas, increased
rainfall could enhance the land degradation process in
these areas through
surface run off, soil erosion, and land slides. This could also
add to the increased sedimentation
loads downstream, reducing the storage
capacity of our limited
reservoirs and eventually could decrease water for
irrigation systems in the
country.
Implications for Agriculture:
Unlike water, positive
benefits are expected due to increases in temperature in the
high-mountain areas.
Recent research conducted by Hussain and Mudasser (2004)
has already shown that
rising temperatures during the winter season has caused
shortening of the Growing
Season Length (GSL) for wheat crop in Swat and
Chitral districts. This
shortening of the GSL has a positive impact on wheat yield
in Chitral valley located
in the high-mountain areas, but has a negative impact on
wheat yield in Swat
valley located in the sub-mountain region.
of mountain region.
Nonetheless, the rising trends in temperature particularly in
the winter season and in
the subsequent transitional period of April-May as
observed in our analysis
for the high-mountain region provides sufficient evidence
that wheat yields and
other similar winter crop yields (e.g. barley) could well be
benefiting from rising
trend in temperatures. Future increases in temperature would
increase the possibility
of growing probably two or more crops per year in the
mountain areas. Wheat
crop area might also expand in these high mountain areas
above 1,500 meters
altitude because the corresponding shortening of the GSL
would make it possible
for wheat crop to reach to its maturity. [Until recently,
wheat crop above 1,500
meters in most years does not reach to timely maturity as
such was prematurely
harvested for fodder production].
Name Height Mountain Range
K2 8611 Karakoram, Baltoro
Glacier
Nanga Parbat 8126 Himalaya
Gasherbrum I 8068 Karakoram,
Baltoro Glacier
Broad Peak 8047 Karakoram,
Baltoro Glacier
Gasherbrum II 8035 Karakoram,
Baltoro Glacier
7000-8000
Meters
Name Height Mountain Range
Gasherbrum III 7952 Karakoram,
Baltoro Glacier
Gasherbrum IV 7925 Karakoram,
Baltoro Glacier
Disteghil Sar 7885 Karakoram,
Shimshal, Muztagh
Kunyang Chhish 7852 Karakoram,
Hispar-Muztagh
Batura I 7795 Karakoram, Batura
Muztagh
Rakaposhi 7788 Karakoram,
Rakaposhi-Haramosh Muztagh
Batura II 7762 Karakoram,Batura
Wall
Kanjut Sar 7760 Karakoram, Hispar
Muztagh
Batura I 7755 Karakoram, Batura
Wall
Saltoro Kangri 7742 Karakoram,
Saltoro Valley
Batura III 7729 Karakoram, Batura
Wall
Trivor 7728 Karakoram, Hispar
Muztagh
Tirich Mir 7706 Hindukush
Chogolisa I 7665 Karakoram,
Baltoro Glacier
Shishpar Sar 7611 Karakoram,
Batura Muztagh
Silberzacken 7597 Himalaya, Nanga
Parbat Region
Batura IV 7594 Karakoram, Batura
Wall
Unknown 7581 Karakoram, Batura
Wall
Yukshin Garden 7530 Karakoram,
Hispar Muztagh
Passu Peak West 7500
Karakoram,Passu Massive
Pumari Chhish W 7492 Karakoram,
Hispar Muztagh
Noshaq 7492 Hundu Kush
Passu Sar 7476 Karakoram, Batura
Muztagh
Malubiting W 7458 Karakoram,
Rakaposhi-Haramosh Muztagh
Muchu Chhish (BaturaV) 7453
Karakoram, Batura Muztagh
Sia Kangri 7422 Karakoram,
Baltoro Glacier
Haramosh 7409 Karakoram,
Rakaposhi-Haramosh Muztagh
Istoro-o-nal 7403 Hindu Kush
Unknown 7400 Karakoram, Batura
Wall
Ultar I Peak 7388 Karakoram,
Batura Muztagh
Sherpi Kangri 7380 Karakoram,
Saltoro Valley
Saraghrar 7349 Hindu Kush
Momhil Sar 7343 Karakoram, Hispar
Muztagh
Jutmo Sar 7330 Karakoram, Hispar
Muztagh
Bojohagur Duanasir 7329
Karakoram, Batura Muztagh
Yazghill 7324 Karakoram, Shimshal
& Boiber Valleys
Unknown 7300 Karakoram, Concordia
& Baltoro Glacier
Passu Diar 7295 Karakoram, Batura
Muztagh
Unknown 7295 Karakoram, Passu
Massive, Hunza Valley
Malubiting C 7291 Karakoram,
Rakaposhi-Haramosh Muztagh
Baintha Brak 7285 Karakoram,
Biafo Glacier
Passu Peak 7284 Karakoram, Passu
Massive
K6 7281 Karakoram, Hushe Valley
Baltoro Kangri 7280 Karakoram,
Baltoro Glacier
Unknown 7280 Karakoram, Batura
Wall
Unknown 7274 Karakoram, Concordia
& Baltoro Glacier
Muztagh Tower 7273 Karakoram,
Baltoro Glacier
Diran 7257 Karakoram,
Rakaposhi-Haramosh Muztagh
Lupgar Sar C 7200 Karakoram,
Hispar Muztagh
Karum Koh 7164 Karakoram,
Shimshal & Boiber Valleys
Hachindar Chhish 7163 Karakoram,
Batura Muztagh
Snow Dome 7160 Karakoram, Baltoro
Glacier
Latok I 7151 Karakoram, Biafo
Glacier
Kampir Dior 7143 Karakoram,
Batura Muztagh
Unknown 7133 Karakoram, Concordia
& Baltoro Glacier
Kunyang Chhish N 7108 Karakoram,
Hispar Muztagh
Udren Zom 7108 Hindu Kush
Kunyang Chhish 7108 Karakoram,
Biafo Hispar
Ghenta Peak 7090 Karakoram, Hunza
Valley
Riakot Peak 7070 Himalaya, Nanga
Parbat Region
Sangemarmar Sar 7050 Karakoram,
Hunza Valley
Link Sar 7041 Karakoram, Hushe
Valley
Spantik 7027 Karakoram,
Rakaposhi-Haramosh Muztagh
Mulungutti Sar 7025 Karakoram,
Hispar Muztagh
Akher Chhish 7020 Hindu Kush
Pamiri Sar 7016 Karakoram, Batura
Muztagh
Rakaposhi East 7010 Karakoram,
Rakaposhi & Bagrot Valley
Unknown 7004 Karakoram, Concordia
& Baltoro Glacier
6000-7000
Meters
Name Height Mountain Range
Laila Peak 6986 Karakoram,
Bagrot-Haramosh Valleys
K7 6934 Karakoram, Hushe Valley
Beka Brakai Chhok 6882 Karakoram,
Batura Wall
Vigne Peak 6874 Karakoram,
Baltoro Glacier
Koyo Zom 6871 Pechus Glacier,
Kishmanja
Dut Sar 6858 Karakoram, Shimshal
& Boiber Valleys
Angel Sar 6858 Karakoram, K2
& Concordia
Latok III 6850 Karakoram,
Bisfo-Hispar
Chongra Peak 6830 Himalaya, Nanga
Parbat Region
Miar Peak 6824 Karakoram,
Bagrot-Haramosh Valleys
Rhuparash 6785 Karakoram, Upper
Nagar
Biarchedi 6781 Karakoram, Baltoro
Glacier
Seiri Porkush 6771 Karakoram,
Batura Glacier West
F Trango Tower 6763 Karakoram,
Baltoro Glacier
Choricho 6756 Karakoram, Braldu
River Valley
Biale Peak 6729 Karakoram,
Muztagh Glacier
Trinity Peak 6700 Karakoram,
Baltoro Glacier
Mani Peak 6685 Karakoram,
Bagrot-Haramosh Valleys
Thui I 6660 Ponarillo Glacier,
Kishmanja
Gul Lasht Zom 6657 Hindu Kush,
Lutkho Valley
Piaju Peak 6610 Karakoram, Braldu
River Valley
Makrong Chhish 6607 Karakoram,
Bisfo-Hispar
Gonalo Peak 6606 Himalaya, Nanga
Parbat Region
Phuparash Peak 6574 Karakoram, Bagrot-Haramosh
Valleys
Buni Zom 6550 Hindu Kush, Shishi
& Golen Valleys
Thui II 6523 Shetor Glacier, Thui
Pass
Ghamubar I 6518 Ghamu Bar Glacier
, Darkot
Noukarsich 6496 Karakoram,
Lupghar Massive, Hunza
Honbrok 6459 Karakoram, Hushe
Valley
Ghamubar II 6432 Ghamubar
Glacier, Darkot
Uli Biaho 6417 Karakoram, Braldu
River Valley
Koser Gunge 6401 Karakoram,
Braldu River Valley
Namika Peak 6325 Karakoram, Hushe
& Shyok Valleys
Urdukas I 6320 Karakoram, Baltoro
Glacier
Bullah 6294 Karakoram, Braldu
River Valley
Purian Sar 6293 Karakoram, Pakore
Pass
Mango Gusor 6288 Karakoram,
Braldu River Valley
Great Trango Tower 6286
Karakoram, Baltoro Glacier
Gama Sokha Lumbu 6282 Karakoram,
Braldu River Valley
Urdukas II 6280 Karakoram,
Baltoro Glacier
Hunza Peak 6270 Karakoram, Hunza
Valley
Marbal Peak 6256 Karakoram,
Concordia & Baltoro Glacier
Crystel Peak 6252 Karakoram,
Concordia & Baltoro Glacier
Ghuchhar Sar 6249 Hindu Kush,
Shishi & Golen Valleys
Garmush 6244 Garmush Glacier,
Darkot
H Trango Tower 6239 Karakoram,
Baltoro Glacier
Lobsang 6225 Karakoram, Baltoro
Glacier
Blatts Yaz 6191 Ghamubar Glacier,
Darkot
Thui Zom 6158 Ghamubar Glacier,
Darkot
Bilchar Dubani 6134 Karakoram,
Bagrot-Haramosh Valleys
Urdukas III 6130 Karakoram,
Baltoro Glacier
Chikar Zom 6110 Chatebori
Glacier, Darkot Pass
Uli Biaho Tower 6109 Karakoram,
Braldu Ruver Valley
Tupopdan 6106 Karakoram, Shimshal
& Boiber Valleys
Darmyani 6090 Karakoram, Lupghar
Massive, Hunza
Mingli Sar 6050 Karakoram,
Shimshal & Boiber Valleys
Balti Peak 6050 Karakoram, Hushe
Valley
Mitre Peak 6025 Karakoram,
Concordia
Bublimating 6000 Karakoram, Hunza
Valley
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good job
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