Water Area
Resume:
November **** Vol.** No.**: **** ****
Geography
doi: 10.1007/s11434-011-4720-8
Recent glacial retreat and its effect on water resources
in eastern Xinjiang
LI KaiMing1,2*, LI ZhongQin1,3, GAO WenYu3 & WANG Lin1
1
Cold and Arid Region Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
2
Lanzhou City University, Lanzhou 730070, China;
3
College of Geography and Environment Science, Northwest Normal University, Lanzhou 730070, China
Received April 29, 2011; accepted July 26, 2011; published online September 12, 2011
The eastern Xinjiang Basin is desperately short of water. Most rivers in the basin originate in the high eastern Tianshan, which has
abundant precipitation and numerous alpine glaciers. Fieldwork conducted on three reference glaciers around Mt. Bogda in 1981
and 2009 suggests that they all strongly melt in summer, a process that has tended to accelerate in recent decades. Based on topo-
graphic maps from 1962 and 1972 and 2005/2006 satellite imagery, we investigated 203 glaciers near Mt. Bogda and 75 glaciers
near Mt. Harlik. The results show that the surface area of the Mt. Bogda glaciers decreased by 21.6% (0.49% a 1) from 1962 to
2006. This was accompanied by a 181 m decrease in length and a 28% drop in ice volume. In the Mt. Harlik region, areal extent
was reduced by 10.5% (0.32% a 1), length by 166 m, and volume by 14% between 1972 and 2005. South-facing glaciers lost
more of their area than those that are north facing, yielding an areal loss of 25.3% and 16.9% for southern and northern slopes of
Mt. Bogda, respectively, and 12.3% and 6.6% for the comparable slopes of Mt. Harlik. Glaciers smaller than 0.5 km2 in area ex-
perienced the strongest retreat, whereas glaciers larger than 2 km2 in area experienced gentle recession but may be the main con-
tributors in the future to river runoff. Glacial ablation in eastern Xinjiang tends to be strong, and the water resources in this region
are deteriorating. Also, a heavy reduction in the capacity of the local karez system, as well as a significant change in river runoff,
can be related to glacial retreat. Combined, this will adversely affect the downstream city of Urumqi and the Turfan Basin.
glacial change, glacier retreat, eastern Xinjiang, remote sensing, water resources, runoff
Li K M, Li Z Q, Gao W Y, et al. Recent glacial retreat and its effect on water resources in eastern Xinjiang. Chinese Sci Bull, 2011, 56: 3596 3604, doi:
Citation:
10.1007/s11434-011-4720-8
Climate change is of great concern the world over, particu- mate change because a small change in climatic parameters
larly regarding the effect of humanity on the existing envi- will result in pronounced geometric changes in glacier
ronment and vice versa. Under continued warming over the shape and size. Many studies show that strong glacial wast-
last several decades, alpine glacier retreat has accelerated. age has been the major trend [3,4] over the period from
Surface melting has occurred even on high-altitude glaciers 1993 to 2003 during which time sea level has risen about
[1]. Moreover, about 75% of the fresh water of the world 0.77 0.18 mm as a result, primarily, of that glacier melting
comes from glaciers [2], thus retreating glaciers will have a [5]. Using two climate models, sea level is estimated to rise
strong influence on the regional hydrologic balance and 0.046 m and 0.051 m as a result of mountain glaciers and
economic sustainability. Climate warming, regardless of ice caps melting by 2100 [6]. The estimate of China s po-
whether it is caused by anthropogenic factors or by nature, tential contribution to cryospheric change is a sea level rise
of 0.14 0.16 mm a 1, of which the contribution of meltwa-
has led to strong global glacier recession. In fact, changes in
ters from glaciers is assessed at about 0.12 mm a 1 [7]. The
alpine glaciers are one of the best natural indicators of cli-
problems associated with strong mountain glacier melt are
glacial hazards such as glacial lake outburst floods and
*Corresponding author (email: ******@***.***)
The Author(s) 2011. This article is published with open access at Springerlink.com csb.scichina.com www.springer.com/scp
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Li K M, et al. Chinese Sci Bull November (2011) Vol.56 No.33
debris flows [8,9], which may increasingly threaten human nental Asia, is far from the sea and experiences severe dry
life and property. Moreover, glacier shrinkage in some re- weather conditions. Annual precipitation is no more than
gions in central Asia may result in serious water shortages 200 mm on the southern slopes of eastern Tianshan, and
in the future, where such supplies depend primarily on less than 100 mm in the foothills to the south. However,
glacier-fed rivers. precipitation markedly increases with altitude, exceeding
600 mm a 1 near the glacier equilibrium line [22,23]. The
Glacier shrinkage in recent decades has made a great
difference to the northwest arid regions of China [10,11]. In extended mountain range, running from east to west, in-
the eastern Xinjiang Basin, an extremely arid region of cludes the Harlik, Barkol and Bogda mountains (Figure 1).
China, meltwater from the Mt. Bogda glaciers strongly af- Controlled by high atmospheric pressure from Mongolia in
fects regional water supplies. The Turfan-Hami oasis, in winter, this region is dry and cold. Whereas in summer, the
particular, has particularly benefited from glacier melting. area is influenced by westerly circulation with plentiful pre-
With regards to glacial melt runoff, the northern slope of Mt. cipitation. Near Mt. Bogda, two large gaps to the east and
Bogda supplies 37.6% of the water for the Baiyang River west of the mountain range enable air masses to pass
Basin [12]. Also, the southern slope of the mountain pro- through the Tianshan carrying more precipitation for glacier
vided reliable water for the Turfan-Hami and Caiwopu ba- development. One of the fundamental characteristics of the
sins. The estimated glacial melt was about 46.9% in the mountain region is that it provides possible conditions for
Heigou River in the 1980s [13]. Meanwhile, the water flow additional precipitation, even in the form of solid ice masses.
of karez systems has decreased in recent decades due to The high eastern Tianshan offers a reliable water supply and
glacial retreat upstream and excessive exploitation of ground- affects the various climate and landscape structures between
water in Turfan. As a result, the usefulness of karez systems the southern and northern slopes [22].
has been greatly reduced. Emphasis on glacial monitoring Based on the Inventory of Chinese Glaciers (CGI) [23],
and investigations is needed as climate change continues in 469 glaciers were identified on the Bogda mountain range
eastern Xinjiang. Such work is needed for the development in the 1960s, the range with the largest number of modern
and utilization of water resources, as well as for ecological alpine glaciers in eastern Tianshan. There were 213 glaciers
assessments. distributed on the northern slopes of the range covering
91.50 km2, and an ice volume of 4.20 km3. The mean area of
Both air temperature and precipitation have experienced
glaciers was 0.43 km2. In contrast, 256 glaciers were located
increasing trends in Xinjiang over the last five decades
(0.67 mm a 1 for precipitation and 0.027 C a 1 for mean air on the southern slopes covering an area of 122.35 km2, with
an ice volume of 6.16 km3 and a mean glacier area of 0.48 km2.
temperature (MAT) [14]). In particular, air temperatures
over the whole of Xinjiang, including the Tianshan moun- Glaciers in eastern parts of Tianshan are less common. The
tain region, have risen significantly since the mid 1980s Barkol mountain range had 57 glaciers with a mean area of
0.53 km2; the Harlik mountain range had 122 glaciers with a
[15 18]. Alpine glaciers frequently occupy the uppermost
mean size of 1.03 km2. Including the 96 glaciers in the Mt.
reaches of river basins here, and these distributed glaciers
Tennger and Mt. Alagou regions, there were a total of 446
have a clear influence on rivers under such climatic condi-
glaciers in eastern Xinjiang (Table 1). Glaciers on the south-
tions. Streamflow in most rivers exhibited a tendency to
ern and northern slopes belong to the Turfan-Hami and
increase, starting in the early 1980s, accompanied by a cal-
Junggar basins, respectively.
endar advancement of the spring flood, putting off of the
The Bogda and Harlik mountain ranges were selected for
summer flood, and increasing the flood peak. For glacier-
investigation for the following reasons. (1) Previous inves-
fed rivers, the timing of the spring flood was relatively sta-
tigations of glaciers (Sigong River No. 4, Heigou No. 8 and
ble, but the flood flow was augmented [19]. There is com-
a fan-shaped glacier) in the Mt. Bogda area and position
plex interaction between glaciers and climate [20]. Glaciers
monitoring of a glacier (Miaoergou ice cap) on Mt. Harlik
in upper-reaches of a basin have an important role in
have contributed to studies of ablation, debris cover and
smoothing out the annual variations in streamflow. This is
glacial distribution in the region. (2) The glacier area around
an essential process in some environments that maintains
Bogda peak accounted for 75% of the total for Mt. Bogda. It
the downstream supply of water, particularly in dry periods
is also the largest glacial region in eastern Tianshan. The
[21]. Generally, rivers in the eastern Xinjiang Basin, where
number and areal extent of glaciers near Mt. Bogda ac-
small glaciers are common, are mainly supplied by glacier
counted for 63% and 52% of the interior drainage area of
and snow melt, and precipitation from the surrounding
eastern Tianshan. (3) Mt. Harlik is situated in the eastern-
mountainous regions. Thus, knowing the relationship be-
most Tianshan, where the southern, northern and eastern
tween climate, glaciers and runoff is essential.
peripheries are surrounded by arid desert environments.
Moreover, the region is located where air masses from the
1 Study area and data Pacific and Indian oceans in the east meet Arctic and Atlan-
tic systems on the west [24]. (4) There is a great difference
The eastern Xinjiang Basin, located in the interior of conti- in average glacier size between the two study sites, with an
3598 Li K M, et al. Chinese Sci Bull November (2011) Vol.56 No.33
Figure 1 Location of investigated regions (black dots represent meteorological stations).
Table 1 Summary of distributed glaciers in upper reach of eastern Xinjiang (areas in km2)
Turfan-Hami Basin Junggar Basin Total
Mountain range CGI This study CGI This study CGI This study
Num. Area Num. Area Num. Area Num. Area Num. Area Num. Area
Bogda 256 122.4 104 81.3 213 91.5 99 62.8 469 213.9 203 144.1
Barkol 21 12.1 36 17.9 57 30.0
Harlik 73 76.6 50 66.3 49 49.3 25 32.0 122 125.9 75 98.3
Tennger 67 29.2 67 29.2
Alagou 29 12.5 29 12.5
Total 446 252.8 174 147.6 298 158.7 124 94.8 744 411.5 278 242.4
average area of 0.46 km2 in the Bogda mountain range and to an accuracy of
1.03 km2 in the region farther to the east. This size distribu- were co-registered and orthorectified using the corrected
tion can be used to examine differences in glacier change topographic maps. To do this, clearly distinguishable terrain
between regions with different glacier sizes. features were used to determine the locations of ground
The satellite images used in this work were acquired control points. Twenty-four ground control points were taken
during nearly cloud-free conditions and for an ablation pe- from 1:50000 scale maps for orthorectification and co-regis-
riod when the extent of snow cover was minimal, thereby tration of the ASTER and SPOT5 images. The registration
reducing the potential uncertainty in glacier mapping. The error was limited to 10).
2 Results has accelerated, based on remote sensing data.
The fan-shaped glacier, situated on the northern slopes of
2.1 Glacial change in the Bogda region
Bogda Peak, is integrated with Glacier Sigong River
No. 5 (5Y725D5) and glacier Gubanbogda River No. 11
(1) Glacier shrinkage. The CGI lists 469 glaciers in the
Mt. Bogda region from 1962 covering 213.9 km2 with an (5Y812B11), the meltwaters of which flow into the Sigong
average size of 0.46 km2 (Table 1). However, only 203 of River to the north and the Gubanbogda River to the south,
respectively. The glacier is 10.94 km2 in area, 4.7 km long,
these glaciers are included in this study, covering 144.1 km2
with an average area of 0.71 km2. This corresponds to 67% and its ablation zone is about 31% of the total glacier area.
The maximum altitude is close to the top of Bogda Peak
of the glaciated area in the region. The total area of those
glaciers was reduced to 112.9 km2 in 2006, indicating a loss (5445 m a.s.l.). Its west side is a steeper avalanche region,
which is a source of glacier mass accumulation. Wu et al.
in area of 21.6% over 44 years (0.5% a 1). About 84% of
[31] suggested that the south termini has retreated at a rate
these glaciers are less than 1 km2 in area. Regions dominat-
of 7.6 m a 1 since the 1930s, greater than the 5.0 m a 1 of
ed by small glaciers are generally more sensitive to change
the north termini retreat rate. Results from our study show
because of the shorter response time to climate variability
that the south termini retreated 509 m (11.6 m a 1), and 272 m
for small glaciers [29,30]. Thus, there is a considerable bias
(6.2 m a 1) to north termini from 1962 to 2006.
toward the great quantity of small glaciers that were re-
duced in area (Figure 2). Moreover, 12 glaciers smaller than Glacier Heigou No. 8 is situated on the southern slope of
0.2 km2 in area completely disappeared during the time pe- Bogda Peak. Its CGI-reported details were an area of
5.61 km2, a length of 7.1 km, and an altitude range of 3380
riod. Larger glaciers tend to extend down to lower eleva-
tions, whereas smaller glaciers have higher termini. How- 5445 m a.s.l. This is a big valley glacier with two firn basins.
ever, when subjected to climate warming, differences in Its supply mainly depended on avalanches. The volume
introduced by avalanches amounted to about 3.0 106 m3 a 1,
area loss for different sizes of glaciers depends less on the
elevation of the glacier and more on their area. In our ex- half of the total supplement. However, the toe of this glacier
ample, glaciers that initially extended over more than 2.0 changed relatively insignificantly from 1962 to 1980 [31].
km2 had an area loss of 8%, whereas glaciers initially That said, its terminus receded 230 m, and reduced in area
smaller than 1.0 km2 lost 33% of their area. by 1.3% over the period from 1962 to 2006. This indicates
Glacier Sigong River No. 4 (5Y725D4) is a gently slop- that great retreat has happened since the 1980s. The in-situ
ing cirque-valley glacier with an area of 2.96 km2 and investigations witnessed strong ablation in summer, and a
length of 3.2 km. The glacier terminus retreated at a rate of glacier surface that was markedly thinned. The maximum
12 m a 1 during the period from 1959 to 1962, and 6 m a 1 thickness away from the glacier toe at 3250 m a.s.l., meas-
from 1962 to 1981, as estimated from the position of reces- ured by Wang, was 192 m in 1986 [32]. This value de-
sional moraines [31]. In total, the glacier terminus retreated creased to 157 m as measured by the Tianshan Glaciology
336 m, or 7.6 m a 1 from 1962 to 2006, and 8.9 m a 1 from station in 2009.
(2) Differences between southern and northern slopes.
1981 to 2006, indicating that the retreat of the glacier terminus
3600 Li K M, et al. Chinese Sci Bull November (2011) Vol.56 No.33
Glaciation in the Bogda region is dominated by small glaci- climate changes. For example, the mean length of glaciers
ers that have experienced extensive losses in area. There are on the northern side of Bogda Peak was 1022 m, which is
also great differences in the changes observed over the last 147 m shorter than those in the southern side (1169 m). This
few decades between glaciers located on the southern and is partly explained by the long and less steep flanks on the
northern slopes. The 104 glaciers studied on the southern southern side that favors long-tongue glacier development.
slopes decreased in total area by 25.3% from 1962 to 2006, However, retreat is fast on the southern side where the ter-
mini have retreated an average of 200 m (4.5 m a 1) com-
while the 99 glaciers on northern slopes reduced in total
pared with 160 m (3.6 m a 1) on the northern side.
area by 16.9%. One reason for this difference is that the
southern slopes at this location receive more direct solar
radiation, which is favorable for glacier ablation. Another 2.2 Glacial change in the Miaoergou region
reason is the asymmetry of the mountains [23]. In general,
The investigation of glaciers in the Miaoergou region cov-
the southern slopes are less steep than the northern slopes;
ered by SPOT5 imagery identified 75 glaciers with a mean
the southern slopes also have long flanks. This southern
area of 1.31 km2, slightly larger than the mean area (1.03 km2)
topographical configuration contributes to the formation of
in the Mt. Harlik region (Table 1). Of these glaciers, 50
larger glaciers. Unfortunately, such glaciers may also ex-
were located on the southern side and 25 were on the north-
pose more of their area to the ablation zone, thereby result-
ern side. The overall glaciated area decreased by 10.5%
ing in greater losses in area.
(0.3% a 1) from 1972 to 2005. On average, the area lost for
Figure 3(a) shows that the area loss of glaciers decreased
each of the 75 glaciers was 0.137 km2, with a terminus re-
with class size. The range of relative area loss in each class
treat rate of 5.0 m a 1 [34]. Glaciers 5 km2 (ac-
on the southern slopes is more than those on the northern
slopes. This is another reason for such strong area losses counting for 5.3% of the total glacier number) decreased in
total area by 1.77 km2 (7.8%). The maximum area loss oc-
from glaciers on the southern slopes, indicating that the dis-
curred in the size class of 1 5 km2, which decreased in total
tribution of class size affects the mean area loss in a region.
area from 59.0 km2 to 53.9 km2, or by 8.6% (Figure 4).
Figure 3(b) shows that the 12 vanished glaciers in this ex-
ample all started out as smaller glaciers (5 km2
the northern slope were located at an altitude range of
3700 4100 m a.s.l. This suggests that some glaciers will in area.
retreat to a higher altitude where they either stabilize or Overall, glacial coverage decreased by 12.3% and 6.6%
disappear under continued climate warming, which is af- for the southern and northern slopes, respectively, from
fected by orientation, slope, glacier type and other topo- 1972 to 2005, indicating a significantly stronger area loss on
graphic factors. the south side glaciers of Mt. Harlik. The Miaoergou ice cap
The variability of glacier length is a delayed and indirect (5Y822C3), located on the southern slope of the mountain,
response to climate change [33]. The cumulative retreat in has a history of glacial field monitoring. Its thickness de-
length is often the most directly observable evidence of past creased by about 5 m at an altitude of 4295 4357 m a.s.l.
Figure 3 Differences in change of glacier area between southern and northern slopes. (a) Area distribution and area change; (b) distribution of vanished
glaciers.
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Li K M, et al. Chinese Sci Bull November (2011) Vol.56 No.33
The areal extent of glaciers is in itself an important in-
fluencing factor for glacier change. As reported above, the
mean glacier sizes in the Bogda and Miaoergou regions, as
calculated from topographical maps from 1962 and 1972,
were 0.71 km2 and 1.31 km2, respectively. This resulted in
corresponding area losses of 21.6% (over 44 years) for
Bogda and 10.5% (over 33 years) for Miaoergou. A greater
loss in area occurred at Bogda, which has a greater quantity
of small glaciers. Glacier area A and its mean annual area
change y approximately satisfy the following nonlinear ex-
ponential relationship: y = a Ab, where a and b are fitting
parameters (Figure 5). The annual change in area decreased
in magnitude as the area increased. Differences exist be-
tween the fitting curves. This trend implies that most large
Figure 4 Distribution of area and number of glaciers in Miaoergou.
glaciers will decrease in size, and would tend to lose more
of their area over shorter response times if climates continue
from 1981 to 2007 [35]. This reduction was the highest in to become warmer.
the middle and lower parts of the ice cap, and there was no Changes in glacier dimensions have a close relationship
significant thinning in the upper region. Analysis of ice with local climate variability. Air temperature and precipi-
cores from this glacier show that ablation accelerated in the tation are the main factors governing accumulation and ab-
most recent 20 30 years. Comparisons between SPOT5 lation in a glacier. For instance, the ice loss caused by an
imagery from 2005 and topographic mapping from 1972 increase of air temperature of 1 C would need an increase in
show that the area of the ice cap decreased from 3.64 km2 to precipitation of 25% to offset the change in mass [3]. Glacier
3.28 km2 (9.9%) and its terminus retreated 77 m (2.3 m a 1) change therefore mirrors climate change for a given time. As
on average. a result, past climate information can be extracted from the
records of glacier change frozen in a particular glacier. Six
meteorological stations were selected in this region (Table 2,
3 Discussion locations in Figure 1). Statistical analysis of data from these
stations indicates that air temperature and precipitation in-
3.1 Regional differences
creased to some degree between 1959 and 2002 ( T > 0,
P > 0). However, regional differences were observed with
Changes in glacier dimensions from different regions may
be affected by humidity, air temperature, precipitation and the MAT of the northern stations (Qitai, Yiwu, Urumqi)
topographical setting. For example, consider the 28% re- were lower than those for the southern stations (Turfan,
duction in glacial coverage observed for the period 1963 Qijiaojin, Hami). Precipitation was just the reverse. MAT
2000 in the Sokoluk watershed of the northern Tianshan in and annual precipitation in Turfan were 14.4 C and 16.3 mm,
Kyrgyzstan, which involved a clear acceleration of wastage respectively, whereas they were 5.2 C and 193.1 mm in
since the 1980s [36]. Another two examples from the north-
ern and central Tianshan, are the glacial regions of Ak-
shiirak and Ala Archa; from 1943 to 2003, they shrank by
12.8% and 15.8%, respectively, as a result of the significant
increase in summer air temperatures [37]. In contrast, Bolch
[38] suggested that glacier retreat in Zailiyskiy and Kungey
Alatau in northern Tianshan was linked to increased air
temperatures in autumn and winter. The average loss of
glacier ice coverage in this region between 1955 and 1999 is
more than 32%. Narama et al. [39] also linked summer air
temperature increases in central Asia to strong ice losses in
recent decades. However, they attributed regional differ-
ences to local climate settings, the average elevations of
glacier termini and the glacier size distribution. Great dif-
ferences in glacier size have also been reported from the
Qinghai-Tibetan Plateau in China [40,41]. Although the
measurement techniques used and time periods observed Figure 5 Relationship between glacier area and mean annual area change
may affect the results, patterns of strong retreat and differ- (subscript M represents Miaoergou, B represents Bogda in the exponential
entiated regional changes in glacier size are obvious. equation).
3602 Li K M, et al. Chinese Sci Bull November (2011) Vol.56 No.33
Table 2 Summary of trends in air temperature and precipitation (1959 2002) for six meteorological stations
T ( C/10 a) P (mm/10 a)
Stations Location Elevation (m a.s.l.) MAT ( C) P (mm)
Qitai 44 01 N, 89 34 E 794 5.2 0.25 193.1 24.8
Yiwu 43 16 N, 94 42 E 1729 3.8 0.22 97.1 8.5
43 47 N, 87 39 E
Urumqi 935 7.1 0.18 262.6 47.3
Turfan 42 56 N, 89 12 E 345 14.4 0.42 16.3 0.8
Hami 42 49 N, 93 31 E 738 9.9 0.13 37.8 3.9
43 13 N, 91 44 E
Qijiaojin 721 9.7 0.53 37.6 2.1
Qitai (at roughly the same latitude). Overall, air tempera- have experienced strong retreat. Undoubtedly, continuous
tures were higher and precipitation was lower on the south- warming perturbations have resulted in glacier wastage.
Currently, glaciers 1 km2
eastern Tianshan discussed above must be accompanied by
large volumetric ice losses. The relationship between ice in area are the main supplier to water resources, but the reg-
volume and area can be defined as V = c S, where the value ulation effect of such glaciers to river runoff is weakening.
of is 1.36 and 1.25 for glacier and ice cap, respectively Runoff in the Tarim River Basin, which has a large
quantity of glaciers distributed in its upstream reaches, has
[42,43]. However, this formula is limited by the determina-
significantly increased since 1990 due to accelerated glacier
tion of the empirical constant c. Bahr et al. [44] improved
melting [46]. However, a smaller number of glaciers were
this formula by eliminating c. Thus, the estimation of ice
distributed in eastern Tianshan. Gao and Luo [47] suggested
volume depends only on relative area change: (1 + pv) = (1 +
ps) . Where pv is the estimated change in volume, and ps is that the variability of runoff in the region is for a different
reason. For example, the variability of runoff in the Tou-
the change in area.
daogou Stream, a glacier-free river, has increased to have a
Thus, based on the change in area of Bogda glaciers
wider gap between high- and low-flow. Variation in runoff
(21.6%), ice volume shrinkage is estimated to be 28% over
was observed to be closely related to precipitation and air
the 44 years from 1962 to 2006. Considering the southern
temperature. In a glacially fed example, the runoff in the
and northern slopes separately, the estimated volume losses
Guxiang River, which is supplied primarily by a number of
are 32% and 22%, respectively. For Miaoergou glaciers, the
small glaciers, has decreased since 2000 due to glacier re-
calculated total volume loss is 14% for the 33 years from
treat. This contrasts with the runoff of the Yushugou Stream,
1972 to 2005, with 16% loss on southern side and 9% loss
on northern side. The strong ice loss, at a rate of 0.6% a 1 of fed by large glaciers, which has continued to increase, even
though the amplitude of the increases has diminished. Ob-
the Bogda glaciers was a result of their small sizes. This
loss was amplified (to 0.7% a 1) on the southern side of the viously, glaciers distributed in the upper reaches of a river
have an important role in stabilizing runoff. In general, al-
mountains. Therefore, strong ice wastage is a dangerous
pine glaciers collect solid precipitation in the winter or wet
signal for local water supplies.
season and release this precipitation as meltwater to supply
rivers in the summer or dry seasons, thereby keeping river
3.3 Effect on regional water resources
runoff stable. For a river without a glacier supply, the coef-
ficient of variation for runoff is unstable. Floods and debris
The Eastern Xinjiang Basin is seriously water deficient. In
flows are liable to occur in such settings.
terms of available surface water, Turfan has the least and
The shortage of water in the eastern Xinjiang Basin and
Hami is in the bottom three of all the regions of Xinjiang.
in the city of Urumqi is a puzzling problem that limits eco-
The 89 rivers in this region (including the Hami and Turfan)
nomic development and domestic water use. The long es-
have remarkably low annual flow that most river flow is
less than 0.5 108 m3 [45]. Water supply for these rivers relies tablished karez system of Turfan, a great underground hy-
draulic system in which underflow is supplied by the down-
on input from glaciers, snow and precipitation. A recent
ward penetration of glacier meltwater and precipitation, has
study [19] suggests that a clear increase of air temperature
decreased from 1700 wells in the 1950s to 1108 in 2009
and precipitation has occurred since 1985 in eastern Xin-
with the number capable of supplying water limited to only
jiang. Alpine glaciers, especially those on southern slopes,
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Li K M, et al. Chinese Sci Bull November (2011) Vol.56 No.33
278. The Mt. Bogda region is one of the primary water re- tative analyses. More detailed research is needed to confirm
sources for over 2.6 million residents of the city of Urumqi. the calculations made here with the aid of reliable glacier
With increases in water consumption, the demand for water field data. The simulation and projection of future runoff
in Urumqi will soon approach the limit of the water supply. trends are also needed to ascertain the relationship between
Caiwopu Lake, source from the glacier meltwaters of Mt. changes in glacier properties and runoff variability.
Bogda, is an ideal water resource near Urumqi [48]. Since
1992, 0.3 108 m3 of water has been diverted from Caiwopu
This work was supported by the National Basic Research Program of Chi-
Lake into Urumqi, thereby relaxing water stress. If climate
na (2010CB951003), the Knowledge Innovation Program of the Chinese
warming causes ice loss to continue at rates like those re-
Academy of Sciences (KZCX2-EW-311) and the National Natural Science
ported in the present study, downstream water sources will Foundation of China (114*******, 91025012 and 41171057).
also deplete. This could endanger local economic develop-
ment and security of human life.
1 Kehrwald N M, Thompson L G, Yao T D, et al. Mass loss on Hima-
layan glacier endangers water resources. Geophys Res Lett, 2008, 35,
doi:10.1029/2008GL035556
4 Conclusions and future research
2 IPCC, 1996. Climate Change 1995: The Science of Climate Change.
Cambridge: Cambridge University Press, 1996
3 Oerlemans J. Extracting a climates signal from 169 glacier records.
The areal extent of small glaciers in the Bogda region was
Science, 2005, 308: 675 677
observed to decrease by 21.6% from 1962 to 2006 (0.5% a 1), 4 Dyrgerov M B, Meier M F. Twentieth century climate change: Evi-
corresponding to a loss in volume of 28%. In comparison, dence from small glaciers. Proc Natl Acad Sci USA, 2000, 97:
the larger glaciers in the Miaoergou region were reduced in 1406 1411
5 IPCC. Climate change 2007: The Physical Science Basis. Contribu-
area by 10.5% over the period from 1972 to 2005 (0.3% a 1),
tion of Working Group I to the Fourth Assessment Report of the In-
corresponding to a volumetric loss of 14%. Glacier retreat tergovernmental Panel on Climate Change. Cambridge: Cambridge
was also clearly observed to differ for the southern and University Press, 2007
6 Raper S C B, Braithwaite R J. Low sea level rise projections from
northern slopes. We found relative losses in area of 25.3%
mountain glaciers and icecaps under global warming. Nature, 2006,
and 16.9% for Bogda, and 12.3% and 6.6% for Miaoergou,
439: 311 313
on the southern and northern slopes, respectively. Climatic 7 Ren J W, Ye B S, Ding Y J, et al. Initial estimate of the contribution
controls on this process are dominated by air temperature, of cryospheric change in China to sea level rise. Chinese Sci Bull,
2011, 56: 1661 1664
which has significantly increased in eastern Xinjiang during
8 Ding Y J, Liu J S. Glacier lake outburst flood disasters in China. Ann
the last 50 years, and particularly in the last 20 years. Pre-
Glaciol, 1992, 16: 180 184
cipitation has increased as well, but this has not been able to 9 Huggel C, K b A, Haeberli W, et al. Remote sensing based assess-
cover the mass deficit caused by temperature increases. Glacier ment of hazards from glacier lake outbursts: A case study in the
Swiss Alps. Can Geotech J, 2002, 39: 316 330
retreat has been the main trend for past four decades.
10 Yao T, Wang, Y Liu S Y, et al. Recent glacial retreat in High Asia in
Strong ablation of glaciers can produce large quantities
China and its impact on water resource in Northwest China. Sci
of water in the short term, and is apt to produce unexpected China Ser D-Earth Sci, 2004, 47: 1065 1075
hazards. However, ablation also leads to substantial drops in 11 Wang R, Ernst G, Gao Q Z. The recent change of water level in the
Bosten Lake and analysis of its causes (in Chinese). J Glaciol Geo-
the solid water mass of the glacier and an eventual decrease
cryol, 2003, 25: 60 64
in meltwater generation. Additionally, the regulation (bal-
12 Kang E S. Glacial meltwater runoff on the north flank of Mt. Bogda
ance between seasons) of river runoff can even be weak- in Tianshan and its contribution to river flow (in Chinese). J Glaciol
ened. For rivers in glacier-free basins, runoff is mainly con- Geocryol, 1983, 5: 113 122
13 Hu X G, Li N J, Deng S M. Glacier meltwater runoff on the south
trolled by precipitation and tends to have a large interannual
slope of the Bogeda Mt. Taking the Heigou as an example (in Chi-
variability. For rivers in glaciated basins, runoff correlates
nese). J Glaciol Geocryol, 1990, 12: 71 82
well with air temperature and precipitation. Its interannual 14 Xue Y, Han P, Feng G H. Change trend of the precipitation and air
variability is stable, whereas the increase of runoff has be- temperature in Xinjiang since the recent 50 years (in Chinese). Arid
Zone Res, 2003, 20: 127 130
gun to decline. Large glaciers will decrease in size due to
15 Pu Z C, Zhang S Q, Li J L, et al. Facts and features of climate change
strong ice wastage, and this in turn will result in an in-
into warmth and damp in the Tianshan Mountains area in the recent
creased sensitivity of the area to climate change. 36 years (in Chinese). Arid Land Geogr, 2008, 31: 409 415
Alpine glaciers have an important role in the water cycle 16 Hu R J, Fan Z L, Wang Y J, et al. Assessment about the impact of
climate change on environment in Xinjiang since recent 50 years (in
of eastern Tianshan. An understanding of the present state
Chinese). Arid Land Geogr, 2001, 24: 97 103
of glaciers is needed to contribute to the reasonable devel-
17 Jiang F Q, Hu R J. Climate change and flood & drought disasters in
opment and utilization of regional water resources, water Xinjiang during recent 50 years (in Chinese). J Desert Res, 2004, 24:
cycle models and regional economic planning. Although 35 40
18 Du G, Wei S Z, Chang X Z. Analysis on the climate change towards
glacial change for the last few decades was investigated
warming wetting trend in the Sangong River watershed, Xinjiang (in
quantitatively here, the volumetric changes reported were
Chinese). Arid Zone Res, 2005, 22: 111 115
estimated based on an empirical formula. The effect of 19 Chen Y N, Xu C C, Yang Y H, et al. Hydrology and water resources
glacier change to water resources has been limited to quali- variation and its responses to regional climate change in Xinjiang (in
3604 Li K M, et al. Chinese Sci Bull November (2011) Vol.56 No.33
Chinese). Acta Geogr Sin, 2009, 64: 1331 1341 impact on water resources in Xinjiang, northwestern China (in Chi-
20 Oerlemans J, Reichert B. Relating glacier mass balance of Meteoro- nese). Quatern Sci, 2010, 30: 96 106
logical data by using a seasonal sensitivity characteristic. J Glaciol, 35 Li Z Q, Wang F T, Zhu G C, et al. Basic features of the Miaoergou
2000, 46: 1 6 Flat-Topped glacier in east Tianshan mountains and its thickness
21 Casassa G, L pez P, Pouyaud B, et al. Detection of changes in glacial change over the past 24 year (in Chinese). J Glaciol Geocryol, 2007,
run-off in alpine basins: Examples from North America, the Alps, 29: 61 65
Central Asia and the Andes. Hydrol Process, 2009, 23: 31 41 36 Niederer P, Bilenko V, Ershova N, et al. Tracing glacier wastage in
22 Wu G H, Ageta Y, Qiu J Q. Physical geographic features and climat- the Northern Tien Shan (Kyrgyzstan/Central Asia) over the l
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