Research Article Changes in Glaciers and Glacial …downloads.hindawi.com/journals/amete/2014/903709.pdfResearch Article Changes in Glaciers and Glacial Lakes and the Identification

Research ArticleChanges in Glaciers and Glacial Lakes andthe Identification of Dangerous Glacial Lakes inthe Pumqu River Basin Xizang (Tibet)

Tao Che1 Lin Xiao1 and Yuei-An Liou2

1 Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Science LanzhouGansu 730000 China

2 Center for Space and Remote Sensing Research National Central University Chung-Li 32001 Taiwan

Correspondence should be addressed to Yuei-An Liou yueiancsrsrncuedutw

Received 27 October 2013 Accepted 18 December 2013 Published 20 January 2014

Academic Editor Chung-Ru Ho

Copyright copy 2014 Tao Che et alThis is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Latest satellite images have been utilized to update the inventories of glaciers and glacial lakes in the Pumqu river basin Xizang(Tibet) in the study Compared to the inventories in 1970s the areas of glaciers are reduced by 1905 while the areas of glaciallakes are increased by 2676 The magnitudes of glacier retreat rate and glacial lake increase rate during the period of 2001ndash2013are more significant than those for the period of the 1970sndash2001The accelerated changes in areas of the glaciers and glacial lakes aswell as the increasing temperature and rising variability of precipitation have resulted in an increased risk of glacial lake outburstfloods (GLOFs) in the Pumqu river basin Integrated criteria were established to identify potentially dangerous glacial lakes basedon a bibliometric analysis method It is found in total 19 glacial lakes were identified as dangerous Such finding suggests that thereis an immediate need to conduct field surveys not only to validate the findings but also to acquire information for further use inorder to assure the welfare of the humans

1 Introduction

A vast amount of studies has been conducted to increase ourunderstanding on the changing cryosphere and its climateconnection Globally averaged temperature data show anincrease of 085∘C over the period of 1880ndash2012 and the totalincrease between the average of the 1850ndash1900 period and the2003ndash2012 period is 078∘C [1] Due to rising temperaturesthe areas of Chinarsquos glaciers have decreased by 5ndash10 [2]With the accelerated retreat of glaciers glacial lakes have beenexpanding over recent decades [3 4] therefore glacial lakesare also considered to be an indicator of climate change [5]

Some glacial lakes are located in valleys belowglaciers andare dammed by unstable moraines formed during the LittleIce Age Occasionally a moraine breaks releasing the lakersquosstored water and discharging large volumes of water withdebris which causes downstream flooding along the riverchannel This phenomenon generally known as a glacial lakeoutburst flood (GLOF) is one of the most serious disasters to

occur in the Himalayan regions of China Nepal India Pak-istan and Bhutan [6ndash10] To assess GLOFs remote sensingtechniques are cheaper and faster than traditional field inves-tigations and have thus been recommended for investigatingglaciers and glacial lakes [11 12]

Due to the more frequent GLOF events in the Himalayasover the past several decades the risks to human life andproperty located downstream of dangerous glacial lakes haveincreased Substantial progress has been achieved in differentregions of the Himalayas and several criteria have been usedto identify potentially dangerous glacial lakes [13ndash22] TheInternational Centre for Integrated Mountain Development(ICIMOD) in collaboration with partners in different coun-tries has begun to prepare a standardized glacial inventoryfor the entireHinduKush-Himalayan region for use as a basisfor GLOF risk assessment [23]

Among the river basins in the Himalayas the Pumqu andPoiqu river basins are two of the most concentrated areasof glacial lakes A ChineseNepalese joint team carried out

Hindawi Publishing CorporationAdvances in MeteorologyVolume 2014 Article ID 903709 8 pageshttpdxdoiorg1011552014903709

2 Advances in Meteorology

Xizang (Tibet) China

Nepal

86∘E 87

∘E 88∘E 89

∘E

86∘E 87

∘E 88∘E 89

∘E

29∘N

28∘N

29∘N

28∘N

0 50000 100000(m)

BoundaryBasin boundaryNational boundary

Elevation (m)2196minus4027

4027minus4644

4644minus5110

5110minus5678

5678minus8848

N

5o194

5o196

5o193

5o1985o197

Figure 1 Location of the Pumqu river basin and its subbasins

the first expedition to inventory glaciers and glacial lakes inthe Pumqu and Poiqu river basins of Xizang (Tibet) in 1987[24] Later the changes in glacial lakes in post-1986 in thePoiqu river basin were again investigated [5] However afteranother ten years [25 26] the changes in glaciers and glaciallakes have not been studied in detail

The aims of this work are (1) to investigate the changes inglaciers and glacial lakes in the Pumqu river basin based onremote sensing data acquired in 2013 and (2) to identifypotentially dangerous glacial lakes in the Pumqu river basinby integrating the latest criteria from recent reports

2 Data and Methodology

21 Study Area The Pumqu river basin is situated in thesouthwestern region of the Tibet Autonomous Region ofChina (Figure 1) This basin is bounded in the north by theMimanjinzhu Range and in the south by the worldrsquos highestmountain range the Himalayan Range The basin extendsinto the Biakuco continental lake in the westThe YapMoun-tains separate the Pumqu and Poiqu river basins The easternpart of the basin extends to Mountains Qumo Xaya andJoding which border the Nyangqu river a tributary of theYarlungzangbo river The total drainage area of the Pumquriver basin is 25307 km2 The Pumqu river flows throughNepal and into the Ganges through the Kosi Based onhydrological maps and the guidelines of the world glacierinventory (WGI) the Pumqu river basin is subdivided intofive subbasins (Figure 1) which also represent a glacier codebasis

22 Methods TheOperational Land Imager (OLI) andTher-mal Infrared Sensor (TIRS) are instruments on board theLandsat 8 satellite which was launched in February of 2013

In total we acquired five series of Landsat 8 OLITIRS imageswith no or low cloud cover in June 2013 The images usedin this study are Level 1 GeoTIFF Data Products which werepreliminarily calibrated Digital elevation model (DEM) datawith a resolution of 90 meters from the Shuttle Radar Topog-raphy Mission (SRTM) were used to obtain topographicinformation [27]

Glacier and glacial lake datasets collected in the 1970s and2001 were used as historical data [25 26] The original dataobtained in the 1970s included aerial photos and digital topo-graphic maps based on aerial surveys from 1974 to 1983 Thetopographic maps from the 1970s were produced from aerialsurveys and two levels of maps 1 100000 and 1 50000respectively were adopted [25] The original data for 2001included sixteen images from the Advanced SpaceborneThermal Emission and Reflection Radiometer (ASTER) andtwo images from the China-Brazil Earth Resources Satellite(CBERS) and their spatial resolutions were 15m and 30mrespectively In this study panchromatic images (band 8)from Landsat 8 OLI were registered with digital topographicmaps using the software of Earth ResourceData Analysis Sys-tem (ERDAS) Imagine The registration accuracy was within15m (one pixel) in most areas Furthermore the images ofother bands were resized to 15m and were registered usingthe reference information from the panchromatic band

A manual interpretation method was used to outlinethe glaciers and glacial lakes based on false color composite(FCC) images (6 5 and 3 bands) DEM data were used todetermine the divide line of the conjunct glaciers The accu-racy of manual interpretation has been demonstrated asoptimal for identifying glaciers and glacial lakes because itallows for the consideration of both spectral characters andinformation regarding texture patterns shapes and shadowsFinally the spatial attributes of glaciers and glacial lakes werecalculated using the topological analysis function of ArcInfosoftware based on theDEMdata while the physical attributeswere duplicated from the historical data in the 1970s and 2001The volumes of glacier and glacial lake were calculated basedon the areas [28 29]

119881119892= (minus1132 + 5321119860

03

119892

)119860119892times 10minus3

119881119897= 0104119860

142

119897

(1)

where119881119892and119860

119892represent the volume (km3) and area (km2)

of glacier while 119881119897and 119860

119897represent the volume (km3) and

area (km2) of glacial lake respectively It should be noted thatthese two formulas were developed in another research fieldand were not validated in this study Therefore the volumescan only be considered as a reference

To identify potentially dangerous glacial lakes a biblio-metric analysis was adopted to define criteria First reportsassociated with the identification of dangerous glacial lakespublished over the last 10 years were collected Secondoverview and review papers were removed so that onlyoriginal and independent research papers were used to derivethe index of identification Third a two-dimensional tablewas established based on the indices and their frequenciesCorrelated indices were combined such as the area and

Advances in Meteorology 3

Table 1 Summary of glacier inventories in the Pumqu river basin for the 1970s 2001 and 2013 periods

Subbasin Number of glaciers Areas of glaciers (km2) Changing ratio of area () Ice reserve (km3)1970s 2001 2013 1970s 2001 2013 1970sndash2001 1970sndash2013 1970s 2001 2013

5o193 358 333 314 68905 65447 54502 minus502 minus2090 7852 7473 55325o194 110 113 112 29409 28188 27966 minus415 minus491 3250 2901 27255o196 58 37 18 1337 420 199 minus6859 minus8512 043 009 0045o197 226 222 214 28085 25948 25257 minus761 minus1007 2123 1972 18215o198 247 195 181 18448 13057 10416 minus2922 minus4354 1027 732 524Total 999 900 839 146184 133060 118340 minus898 minus1905 14295 13087 10606

Table 2 Summary of glacial lake inventories in the Pumqu river basin for the 1970s 2001 and 2013 periods

Subbasin Number of glacial lakes Areas of glacial lakes (km2) Increasing ratio of area () Lake volume (106 m3)1970s 2001 2013 1970s 2001 2013 1970sndash2001 1970sndash2013 1970s 2001 2013

5o193 62 61 72 915 965 1013 541 1073 20054 22115 215545o194 16 15 15 708 794 747 1209 542 31399 35705 333375o196 37 36 55 935 991 1071 600 1453 28563 30668 313075o197 25 24 36 663 746 1139 1246 7184 17175 20586 333045o198 59 60 76 940 1215 1305 2922 3882 21837 31544 33440Total 199 196 254 4161 4709 5275 1318 2676 119028 140618 152942

volume of a glacial lake or the gradient ratio of a downstreamchannel and the slope of a dam Fourth it was assumedthat the frequently used indices were more important Theseindices were ordered based on their importance and themost important indices were selected as the final criteriaWeight of each criterionwas calculated based on its frequencyof usage Finally all weights of criteria that are conformedto the properties of glacial lake were accumulated as thedangerous degree A glacial lake with the larger degree ismore dangerous

3 Results

31 Distribution and Change of Glaciers and Glacial LakesThe number and areas of glaciers throughout the entire basinand in each sub-basin of the study area were calculated forthe 1970s 2001 and 2013 periods (see Table 1) The glacierswere primarily distributed in the southern region and theaverage area of the glaciers was small The number of glaciersin the Pumqu river basin was 999 in the 1970s 900 in 2001and 839 in 2013The glacier areas were 1462 km2 in the 1970s1330 km2 in 2001 and 1183 km2 in 2013 Over the past fourdecades the number of glaciers decreased by 160 while theglacier area decreased by 27844 km2 (1905) It is found thatsimilar findings are obtained as compared with the previousstudy

It is found that small glaciers decreased faster than largerglaciers in the past four decades (Figure 2) Such findings areconsistent with those found from the previous study [25]However the rate of changes in areas of glaciers during theperiod of 2001ndash2013 is more significant than those for theperiod of the 1970sndash2001 Meanwhile the glaciers in thesouthwest region were relatively stable (5o194 sub-basin)

0

100

200

300

400

500

Num

ber o

f gla

cier

s

1970s20012013

lt01 01minus05 05minus1 1minus5 5minus10 10minus20 gt20

Area (km2)

Figure 2 Changes in number and areas of glaciers for the 1970s2001 and 2013 periods

Table 2 presents the number and areas of glacial lakes inthe Pumqu river basin for the 1970s 2001 and 2013 periodsThe expansion of glacial lake is very clear in the past fourdecades The number of glacial lakes was almost not changedduring the period of 1970sndash2001 while the area of glacial lakeswas increased by 1318 In the past decade more than 50glacial lakes have newly formed and the area of glacial lakesincreased by 2676 over the past four decades Similar tothe changes in glaciers the rate of changes in area of glacial


Table 3 Integrated criteria for identifying potentially dangerous glacial lakes

Index Criteria Frequencies WeightType of glacial lake End moraine-dammed lake 10 015Area of lake Larger than 02 km2 10 015Distance between lake and its mother glacier Smaller than 500m 10 015Average slope of glaciers Larger than 7 degree 7 010Slope of the downstream Larger than 20 degree 7 010Top width of dam Less than 60 meters 7 010Area of glacier Larger than 2 km2 6 009Slope between lake and its mother glacier Larger than 8 degree 5 007Change of lake area Larger than 10 of decade 4 006Elevation of lake Higher than 5000 meters 2 003

lakes during the period of 2001ndash2013 is more significant thanthose for the period of the 1970sndash2001 Similar results werealso obtained in the Poiqu river basin [5]

On the other hand the number of glacial lakes was stablewhile the areas were expanded from the 1970s to 2001 periodsThe number of glacial lakes with areas less than 01 km2 wasdecreased while that with areas between 05 and 10 km2 wasincreased from the 1970s to 2001 periods (Figure 3) Howeverboth the number and areas of glacial lakes have significantlyrisen since 2001 (Figure 3)Thereweremany new glacial lakeswith areas less than 01 km2 and the number of glacial lakeswith larger areas was increased for the period of 2001ndash2013

32 Identification of Potentially Dangerous Glacial LakesMany researchers have reported indices for the identificationof potentially dangerous glacial lakes [29ndash31] In this workstudy areas located in the Tibet Plateau regions were selectedand analyzed to obtain suitable criteria for the Pumqu riverbasin [13ndash22] The indices and criteria used in these tenpapers are listed in Table 3The glacial lake type the distancebetween the mother glacier and the glacial lake the glaciallake area the average slope of the glacier the slope of thedownstream region the dam width the mother glacier areathe slope between the lake and its mother glacier the changein lake area and the lake elevation were adopted as indicesbased on the literature analysis Note that the values withinthe criteria represented most of the previous reports

According to the statistics shown in Table 3 all studiesagreed that an end moraine-dammed lake with an area largerthan 02 km2 for which the distance between the lake and itsmother glacier is less than 500m is dangerous However thelake area was used in seven cases while the lake volume wasused in six cases It is difficult to obtain the lake volumewhichis calculated from the lake area via empirical equations [29]Thus these two indices were combined as the lake area

Most of the studies argued that the average slope of theglacier the slope of the downstream region and the damwidth are important factors Half of the studies consideredthe area of the mother glacier the slope between the lake andits mother glacier and changes in the lake area Only twostudies considered the glacial lake elevation because a higherelevation indicates a greater potential energy once the dam isbroken

lt01 02minus05 05minus10 gt100

40

80

120

160

Num

ber o

f gla

cial

lake

s

1970s20012013

01-02

Area (km2)

Figure 3 Changes in number and areas of glacial lakes for the 1970s2001 and 2013 periods

In addition to the above-mentioned indices the numberof mother glaciers and the height and stability of the damwere each used in two studiesThe number ofmother glacierscan be reflected by the area of mother glaciers while it ischallenging to determine the height and stability of a damfrom remote sensing data Therefore these two indices wereexcluded in the integrated criteria in this work

To identify potentially dangerous glacial lakes in thePumqu river basin the criteria and their weights in Table 3were adopted The SRTM DEM data were used to obtain theslope of the glacier the slope of the downstream region theslope between the lake and its mother glacier and the lakeelevation The areas and changes in glaciers and glacial lakeswere obtained from the datasets for the 1970s 2001 and 2013periods while the width of the dam and the distance betweenthe lake and its mother glacier were measured from the OLIimages

The total weight of each lake was calculated based on thecriteria and weights in Table 3 The dangerous degrees were


Table 4 Number of glacial lakes with different hazard levels in each subbasin

Subbasin Number of glacial lakes Hazard level (total weight)1 (0ndash019) 2 (02ndash039) 3 (04ndash059) 4 (06ndash079) 5 (08ndash10)

5o193 72 11 37 19 4 15o194 15 0 0 8 4 35o196 55 15 31 8 1 05o197 36 2 3 11 9 115o198 76 8 23 21 20 4Total 254 36 94 67 38 19

4

2

3

101

121317

19

8 571815

10121317

8 5

11

7

1469

16

N

0 30000 60000

(m)


4027minus4644

4644minus5110

5110minus5678

5678minus8848

Potentially dangerous glacial lakes

Figure 4 Distribution of potentially dangerous glacial lakes in thePumqu river basin (the ID is according to Table 4)

divided into five levelswith equal interval (eg 02) and thoselakes with highest hazard level were considered as potentiallydangerous Totally there are 19 glacial lakes with the highesthazard level (Table 4) almost all of which are in the southernbasins (particularly in sub-basin of 5o197) where glaciers andglacial lakes are densely located (Figure 4) The potentiallydangerous glacial lakes are recommended for further detailedinvestigations and field surveys because a potential breakoutcould have catastrophic effects on human life and property inChina and Nepal For information to the field work the basicattributes of these lakes were listed in Table 5

Figure 5 shows two examples of the morphologicalchanges of potentially dangerous glacial lakes (GelhaipucoLake and Coqong Lake) Their locations and other charac-teristics are presented in Table 5 the ID of Gelhaipuco is ldquo19rdquoand Coqong Lake is ldquo16rdquo respectively Figure 5 clearly showsthe relationship between glacial lake expansion and motherglacier shrinkage in different periods

4 Discussion

41 Accuracy of Glacier and Glacial Lake Data The glaciersand glacial lakes were mapped by manual interpretationwhich has been considered the most accurate method foroutlining glaciers and glacial lakes However the original

1970s 2001 2013

(m)0

N

2500 5000

(a)

1970s 2001 2013(m)

0 2500 5000

N

(b)

Figure 5 Morphological changes in two dangerous glacial lakes (a)Gelhaipuco Lake and (b) Coqong Lake (Dark blue represents glaciallakes while light blue represents glaciers)

datasets had different spatial resolutions The uncertainty ofthe glacier and glacial lake areas depends on the register accu-racy and the spatial resolution of the remote sensing dataTheregister accuracy is one pixel in most study areas althoughthe error can reach two pixels in very rugged regions Inthe 1970s the original data were obtained from topographicmaps withmap scales of 1 100000 and 1 50000 indicating aspatial resolution of 50m and 25m respectively For the 2001data the resolutions of the ASTER and CBERS images are15m and 30m For the 2013 data the OLI image resolutionhas been enhanced to 15m Therefore the uncertainty canbe calculated based on the register error (119877 times 119877) and theerror induced by the spatial resolution (2 times 119877 times 119877 times radic1)where 119877 is the spatial resolution [32 33] For the lowestresolution (50m) the register error is 00025 km2 and thespatial resolution error is 0005 km2 for the glacier and glacial


Table 5 Potentially dangerous glacial lakes in the Pumqu river basin

ID Subbasin Longitude Latitude Elevation (m) Area (m2)1 5o193 87∘02831015840E 28∘04161015840N 559703 746 0232 5o194 86∘34911015840E 28∘11951015840N 506980 1 381 4603 5o194 86∘22811015840E 28∘23721015840N 546970 925 6284 5o194 86∘18231015840E 28∘22641015840N 534770 3 748 5805 5o197 88∘21241015840E 28∘01421015840N 515085 538 0326 5o197 88∘19251015840E 28∘00371015840N 510419 380 8627 5o197 88∘17261015840E 28∘01041015840N 523712 508 8828 5o197 88∘15471015840E 28∘00671015840N 524075 581 4879 5o197 88∘14451015840E 28∘00361015840N 524471 372 99010 5o197 88∘04421015840E 27∘56961015840N 547938 1 348 83011 5o197 88∘04031015840E 27∘56161015840N 556611 853 07012 5o197 88∘00271015840E 27∘55831015840N 533151 1 147 95013 5o197 87∘55821015840E 27∘57161015840N 501786 1 094 16014 5o197 87∘54491015840E 27∘57071015840N 518323 952 02515 5o197 87∘38391015840E 28∘11681015840N 535283 545 51016 5o198 87∘48641015840E 27∘57871015840N 525975 454 41617 5o198 87∘46211015840E 27∘55611015840N 491894 1 084 74018 5o198 87∘38391015840E 28∘05621015840N 519741 693 13519 5o198 87∘33681015840E 28∘10701015840N 502418 1 013 480

lake areas These errors are very small and can thus beignored However the presence of very small glacial lakesand water ponds in different periods can lead to a largeruncertainty for the number of glacial lakes Therefore glaciallakes with an area larger than 002 km2 were analyzed in thiswork to obtain consistent datasets for the past four decades

One issue that may influence the accurate classifica-tioninterpretation of glacial lakes is the fact that glaciallake areas are always larger in the summer due to the highand concentrated precipitation during the summermonsoonHigh temperatures in summer also result in more watersupplies (primarily melt water from glaciers snow cover andpermafrost terrains) in glacial lakes Therefore when usingremote sensing images for long-term monitoring of glaciallakes one must take temporal consistency into account [34]In this study the dates of remote sensing images acquisitionwere inconsistent with three periods of 1970s 2001 and 2013which may lead to the uncertainties in glacial lake area

42 Changes in Glacier and Glacial Lake Temperature andprecipitation are major factors controlling glacier change andglacial lake activities and are also direct causes of GLOFsAnnually averaged air temperature and precipitation datafrom 1971 to 2012 were acquired at the Dingri meteorologicalstation (Figure 6)The temperature dataweremeasured in theair 2m above the surface and the precipitation data includerainfall snowfall large-scale precipitation and convectiveprecipitation The meteorological data indicate an increas-ing trend in air temperature but not an obvious trend inprecipitation (Figure 6) Besides the trends of temperaturethe monthly maximum air temperature data were collectedfor the evaluation of glacier melting (Figure 7) Because

0

05

1

15

1970 1980 1990 2000 2010

0

100

200

Year

Prec

ipita

tion

(mm

)

Trend of precipitationPrecipitationTemperature Trend of temperature

minus05

minus1

minus15 minus200

minus100

Tem

pera

ture

(∘C)

Figure 6 Anomalies in air temperature and precipitation from 1971to 2012 at the Dingri meteorological station

the elevation of Dingri station is 4300m and the meanelevation of glacial lake is 5100m which can be consideredas the elevation of end of glaciers the air temperatureswere corrected based on minus06∘C per 100m according to theobservations at the nearby meteorological station Howeverthe average air temperature was also higher than 0∘C fromMay to September (the figurewas not shown here)Thereforeboth the temperature and its trend indicate the glacierswere accelerated in melting in summer In agreement withthe previous reports [25 26] it can be concluded thatclimate warming is the main reason for glacier recession inthe Pumqu river basin and hence glacial lake expansionStatistics also showed that with the rising temperatures andincreased variability of precipitation the frequency of GLOFevents is expected to increase [35]


1970 1980 1990 2000 2010

5

8

11

14

17

Year

MayJuneJuly

AugustSeptemberOctober

Tem

pera

ture

(∘C)

Figure 7 Monthly maximum air temperature from 1971 to 2012 atthe elevation of 5100m

43 Potentially Dangerous Glacial Lakes Potentially dan-gerous glacial lakes were identified based on our literatureanalysis as well as remote sensing and DEM data A suddenincrease in temperature can lead to rapid glacier melting(even glacier calving) based on previous reports of historicalGLOF events [16 36 37] High temperatures can also desta-bilize surrounding sediments (eg the moraine dam) Withthe increased temperatures in the Pumqu river basin thepossibility of GLOF events has risen Moreover the interan-nual fluctuations in precipitation for the period of 2000ndash2012were significantly larger than those for the period of 1971ndash2000 The standard deviation of precipitation for the periodof 1971ndash2000 was 8123mm while it grew up to 8555mmfor the period of 2000ndash2012 These extremes in temperatureand precipitation have been persistently increasing underthe background of global changes Thus these potentiallydangerous glacial lakes should receive more attention

Note that the moraine dam properties such as the pres-ence of bedrock ice and pipes cannot be interpreted byremote sensing data with a resolution of 15m [38]Thereforewe recommend that a field survey should be carried out in thenext few years to obtain amore reliable evaluation of the dan-gerous lakes identified in this work For confirmed dangerouslakes substantial mitigationmeasures should be immediatelyimplemented to reduce the risk of outburst This work hasprovided basic information regarding potentially dangerousglacial lakes which is very useful to the organization of fieldwork

5 Conclusion

This study used remote sensing images supplemented byDEM data to update the inventory of glaciers and glaciallakes in the Pumqu river basin Tibetan Plateau The changesin glaciers and glacial lakes over the past four decades werealso analyzedThe results indicate that there are currently 839glaciers and 254 glacial lakes in the study area with total areaof 11834 km2 and 5275 km2 respectively Between the 1970s

and 2013 periods the number of glaciers decreased by 160while the glacier area decreased by 27657 km2 (1905) Theglacial lake area rose by 1114 km2 (2676) and the numberof lakes increased by 55The retreat of glaciers and expansionof glacial lakes (both in number and area) were particularlysignificant during the period of 2001ndash2013

Based on a literature analysis integrated criteria wereestablished for the identification of potentially dangerousglacial lakes Based on these criteria and their weights 19potentially dangerous glacial lakes were identified most ofwhich are located in the southern part of the basinThe outletof the Pumqu river basin is the boundary between Chinaand Nepal so that potential GLOFs could have a catastrophiceffect on lives and properties in the downstream communi-ties Therefore a field survey is recommended to investigatethe dangerous glacial lakes identified in this work and toconduct mitigation measures for highly dangerous glaciallakes

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors appreciate the reviewers for their constructivecomments to improve the quality of the paper Landsat 8 OLIdata were provided by USGS and SRTM DEM data wereprovided by NASA This work was supported by the ChinaState Key Basic Research Project (2013CBA01802) the Chi-nese National Natural Science Foundation (41271356) andNational Science Council (NSC 102-2111-M-008-027 102-2221-E-008-034)

References

[1] Working group I ldquoClimate change 2013 the physical sci-ence basis summary for policymakersrdquo IPCC 5th AssessmentReport 2013

[2] X Li G Cheng H Jin et al ldquoCryospheric change in ChinardquoGlobal and Planetary Change vol 62 no 3-4 pp 210ndash218 2008

[3] T Che L Xin P K Mool and J Xu ldquoMonitoring glaciers andassociated glacial lakes on the east slopes ofMount Xixabangmafrom remote sensing imagesrdquo Journal of Glaciology and Geocry-ology vol 27 no 6 pp 801ndash805 2005 (Chinese)

[4] XWang KWu L Jiang et al ldquoWide expansion of glacial lakesin Tianshan Mountains during 1990ndash2010rdquo Acta GeographicaSinica vol 68 no 7 pp 984ndash993 2013 (Chinese)

[5] X Chen P Cui Y Li Z Yang and Y Qi ldquoChanges in glaciallakes and glaciers of post-1986 in the PoiquRiver basinNyalamXizang (Tibet)rdquo Geomorphology vol 88 no 3-4 pp 298ndash3112007

[6] Y Ding and J Liu ldquoGlacier lake outburst flood disasters inChinardquo Annals of Glaciology vol 16 pp 180ndash184 1992

[7] S K Jain A K Lohani R D Singh A Chaudhary and L NThakural ldquoGlacial lakes and glacial lake outburst flood in aHimalayan basin using remote sensing and GISrdquo Natural Haz-ards vol 62 no 3 pp 887ndash899 2012


[8] P K Mool ldquoGlacier lake outburst floods in Nepalrdquo Journal ofNepal Geological Society vol 11 pp 273ndash280 1995

[9] R Kattelmann ldquoGlacial lake outburst floods in theNepal Hima-laya a manageable hazardrdquo Natural Hazards vol 28 no 1 pp145ndash154 2003

[10] S R Bajracharya and P K Mool ldquoGlaciers glacial lakes andglacial lake outburst floods in theMount Everest region NepalrdquoAnnals of Glaciology vol 50 no 53 pp 81ndash86 2009

[11] S D Richardson and J M Reynolds ldquoAn overview of glacialhazards in theHimalayasrdquoQuaternary International vol 65-66pp 31ndash47 2000

[12] A Kaab C Huggel L Fischer et al ldquoRemote sensing of gla-cier- and permafrost-related hazards in high mountains anoverviewrdquoNatural Hazards and Earth System Science vol 5 no4 pp 527ndash554 2005

[13] R LvA Study of Typical Mountain Hazards Along Sichuan-TibetHighway ChengduUniversity of Science and Technology PressChengdu China 1999 (Chinese)

[14] Z Cheng P Zhu and Y Gong ldquoTypical debris flow triggeredby ice-lake breakrdquo Journal of Mountain Science vol 21 no 6pp 716ndash720 2003 (Chinese)

[15] J Huang C Wang G Wang and C Zhang ldquoApplication offuzzy comprehensive evaluation method in risk degree deter-mination for ice-lake outburst-an example of Luozha county inTibetrdquo Earth and Environment vol 33 supplement 2005

[16] X Chen P Cui Z Yang and Y Qi ldquoRisk assessment of glaciallake outburst in the Poiqu River Basin of Tibet autonomousregionrdquo Journal of Glaciology and Geocryology vol 29 no 4 pp509ndash516 2007 (Chinese)

[17] T Bolch M F Buchroithner J Peters M Baessler and SBajracharya ldquodentification of glacier motion and potentiallydangerous glacial lakes in the Mt Everest regionNepal usingspaceborne imageryrdquo Natural Hazards and Earth System Sci-ences vol 8 no 6 pp 1329ndash1340 2008

[18] X Wang S Liu W Guo F Yu and J Xu ldquoHazard assessmentof moraine-dammed lake outburst floods a in the himalayasChinardquo Acta Geographica Sinica vol 64 no 7 pp 782ndash7902009

[19] Y Shu Hazard assessment of Morine-dammed lake outburstsin the Himalayas Tibet and propagating numerical simulation[MS thesis] Jilin university Jilin China 2011

[20] Z Li T Yao Q Ye C Li andWWang ldquoMonitoring glacial lakevariations based on remote sensing in the Lhozhag DistrictEastern Himalayas 1980ndash2007rdquo Journal of Natural Resourcesvol 26 no 5 pp 836ndash846 2011

[21] L Zhang Outburst susceptiblity estimation of glacier lakes inNielamu Tibet based on presort method [MS thesis] Jilin uni-versity Jilin China 2012 (Chinese)

[22] J Liu Z Cheng and X Chen ldquoThe hazard assessment ofglacier-lake outburst in Palongzangbu Riverrdquo Journal of Moun-tain Science vol 30 no 3 pp 369ndash377 2012 (Chinese)

[23] J D Ives R B Shrestha and P K Mool Formation of GlacialLakes in the Hindu Kush-Himalayas and GLOF Risk AssessmentICIMOD Kathmandu Nepal 2010

[24] LIGGWECSNEA Report on First Expedition to Glaciers andGlacier Lakes in the Pumqu (Arun) and Poique (Bhote-Sun Kosi)River Basins Xizang (Tibet) China Sino-Nepalese Investigationof Glacier Lake Outburst Floods in the Himalaya Science PressBeijing China 1988

[25] R Jin X Li T Che LWu and PMool ldquoGlacier area changes inthe Pumqu river basin Tibetan Plateau between the 1970s and2001rdquo Journal of Glaciology vol 51 no 175 pp 607ndash610 2005

[26] T Che R Jin X Li and L Wu ldquoGlacial lakes variation andthe potentially dangerous glacial lakes in the Pumqu basin ofTibet during the last two decadesrdquo Journal of Glaciology andGeocryology vol 26 no 4 pp 397ndash402 2004 (Chinese)

[27] A Jarvis H I Reuter A Nelson and E Guevara ldquoHole-filled SRTM for the globe Version 4rdquo CGIAR-CSI SRTM 90mDatabase 2008 httpsrtmcsicgiarorg

[28] C Liu and L Ding ldquoThe newly progress of glacier inventoryin TianshanMountainsrdquo Journal of Glaciology and Geocryologyvol 8 no 2 pp 167ndash170 1986 (Chinese)

[29] C Huggel A Kaab W Haeberli P Teysseire and F PaulldquoRemote sensing based assessment of hazards from glacier lakeoutbursts a case study in the Swiss Alpsrdquo Canadian Geotechni-cal Journal vol 39 no 2 pp 316ndash330 2002

[30] R J McKillop and J J Clague ldquoStatistical remote sensing-based approach for estimating the probability of catastrophicdrainage from moraine-dammed lakes in southwestern BritishColumbiardquo Global and Planetary Change vol 56 no 1-2 pp153ndash171 2007

[31] T Bolch J Peters A Yegorov B PradhanM Buchroithner andV Blagoveshchensky ldquoIdentification of potentially dangerousglacial lakes in the northern Tien Shanrdquo Natural Hazards vol59 no 3 pp 1691ndash1714 2011

[32] D K Hall K J Bayr W Schoner R A Bindschadler and JY L Chien ldquoConsideration of the errors inherent in mappinghistorical glacier positions in Austria from the ground andspace (1893ndash2001)rdquo Remote Sensing of Environment vol 86 no4 pp 566ndash577 2003

[33] R S Williams D K Hall O Sigurbsson and J Y L ChienldquoComparison of satellite-derived with ground-based measure-ments of the fluctuations of the margins of Vatnajokull Iceland1973ndash1992rdquo Annals of Glaciology vol 24 pp 72ndash80 1997

[34] C Liu ldquoGlacier lakes and their outburst behaviors in theHimalayas Xizangrdquo in Proceedings of the 4th National Confer-ence on Glaciology and Geocryology (Glaciology) pp 141ndash150Science Press Beijing China 1990 (Chinese)

[35] S R Bajracharya P KMool and B R Shrestha ldquoThe impact ofglobal warming on the glaciers of the Himalayardquo in Proceedingsof the International Symposium on Geodisasters InfrastructureManagement and Protection ofWorldHeritage Sites pp 231ndash2422006

[36] Z Yao R Duan X Dong and C Yu ldquoThe progress and trendsof glacial lakes research on Qinghai-Tibet Plateaurdquo Progress inGeography vol 29 no 1 pp 10ndash14 (Chinese)

[37] M Chiarle S Iannotti G Mortara and P Deline ldquoRecentdebris flow occurrences associated with glaciers in the AlpsrdquoGlobal and Planetary Change vol 56 no 1-2 pp 123ndash136 2007

[38] P Cui D Ma N Chen and Z Jiang ldquoThe initiation motionand mitigation of debris flow caused by glacial lake outburstrdquoQuaternary Sciences vol 23 no 6 pp 621ndash628 2003 (Chinese)

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ClimatologyJournal of

EcologyInternational Journal of


EarthquakesJournal of


Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Mining


Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics

OceanographyInternational Journal of


Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering


GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Atmospheric SciencesInternational Journal of


OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in


MineralogyInternational Journal of


MeteorologyAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Geological ResearchJournal of


Geology Advances in


Xizang (Tibet) China

Nepal

86∘E 87

∘E 88∘E 89

∘E

86∘E 87

∘E 88∘E 89

∘E

29∘N

28∘N

29∘N

28∘N

0 50000 100000(m)

BoundaryBasin boundaryNational boundary


4027minus4644

4644minus5110

5110minus5678

5678minus8848

N

5o194

5o196

5o193

5o1985o197

Figure 1 Location of the Pumqu river basin and its subbasins

the first expedition to inventory glaciers and glacial lakes inthe Pumqu and Poiqu river basins of Xizang (Tibet) in 1987[24] Later the changes in glacial lakes in post-1986 in thePoiqu river basin were again investigated [5] However afteranother ten years [25 26] the changes in glaciers and glaciallakes have not been studied in detail

The aims of this work are (1) to investigate the changes inglaciers and glacial lakes in the Pumqu river basin based onremote sensing data acquired in 2013 and (2) to identifypotentially dangerous glacial lakes in the Pumqu river basinby integrating the latest criteria from recent reports

2 Data and Methodology

21 Study Area The Pumqu river basin is situated in thesouthwestern region of the Tibet Autonomous Region ofChina (Figure 1) This basin is bounded in the north by theMimanjinzhu Range and in the south by the worldrsquos highestmountain range the Himalayan Range The basin extendsinto the Biakuco continental lake in the westThe YapMoun-tains separate the Pumqu and Poiqu river basins The easternpart of the basin extends to Mountains Qumo Xaya andJoding which border the Nyangqu river a tributary of theYarlungzangbo river The total drainage area of the Pumquriver basin is 25307 km2 The Pumqu river flows throughNepal and into the Ganges through the Kosi Based onhydrological maps and the guidelines of the world glacierinventory (WGI) the Pumqu river basin is subdivided intofive subbasins (Figure 1) which also represent a glacier codebasis

22 Methods TheOperational Land Imager (OLI) andTher-mal Infrared Sensor (TIRS) are instruments on board theLandsat 8 satellite which was launched in February of 2013

In total we acquired five series of Landsat 8 OLITIRS imageswith no or low cloud cover in June 2013 The images usedin this study are Level 1 GeoTIFF Data Products which werepreliminarily calibrated Digital elevation model (DEM) datawith a resolution of 90 meters from the Shuttle Radar Topog-raphy Mission (SRTM) were used to obtain topographicinformation [27]

Glacier and glacial lake datasets collected in the 1970s and2001 were used as historical data [25 26] The original dataobtained in the 1970s included aerial photos and digital topo-graphic maps based on aerial surveys from 1974 to 1983 Thetopographic maps from the 1970s were produced from aerialsurveys and two levels of maps 1 100000 and 1 50000respectively were adopted [25] The original data for 2001included sixteen images from the Advanced SpaceborneThermal Emission and Reflection Radiometer (ASTER) andtwo images from the China-Brazil Earth Resources Satellite(CBERS) and their spatial resolutions were 15m and 30mrespectively In this study panchromatic images (band 8)from Landsat 8 OLI were registered with digital topographicmaps using the software of Earth ResourceData Analysis Sys-tem (ERDAS) Imagine The registration accuracy was within15m (one pixel) in most areas Furthermore the images ofother bands were resized to 15m and were registered usingthe reference information from the panchromatic band

A manual interpretation method was used to outlinethe glaciers and glacial lakes based on false color composite(FCC) images (6 5 and 3 bands) DEM data were used todetermine the divide line of the conjunct glaciers The accu-racy of manual interpretation has been demonstrated asoptimal for identifying glaciers and glacial lakes because itallows for the consideration of both spectral characters andinformation regarding texture patterns shapes and shadowsFinally the spatial attributes of glaciers and glacial lakes werecalculated using the topological analysis function of ArcInfosoftware based on theDEMdata while the physical attributeswere duplicated from the historical data in the 1970s and 2001The volumes of glacier and glacial lake were calculated basedon the areas [28 29]

119881119892= (minus1132 + 5321119860

03

119892

)119860119892times 10minus3

119881119897= 0104119860

142

119897

(1)

where119881119892and119860

119892represent the volume (km3) and area (km2)

of glacier while 119881119897and 119860

119897represent the volume (km3) and

area (km2) of glacial lake respectively It should be noted thatthese two formulas were developed in another research fieldand were not validated in this study Therefore the volumescan only be considered as a reference

To identify potentially dangerous glacial lakes a biblio-metric analysis was adopted to define criteria First reportsassociated with the identification of dangerous glacial lakespublished over the last 10 years were collected Secondoverview and review papers were removed so that onlyoriginal and independent research papers were used to derivethe index of identification Third a two-dimensional tablewas established based on the indices and their frequenciesCorrelated indices were combined such as the area and







5o193 62 61 72 915 965 1013 541 1073 20054 22115 215545o194 16 15 15 708 794 747 1209 542 31399 35705 333375o196 37 36 55 935 991 1071 600 1453 28563 30668 313075o197 25 24 36 663 746 1139 1246 7184 17175 20586 333045o198 59 60 76 940 1215 1305 2922 3882 21837 31544 33440Total 199 196 254 4161 4709 5275 1318 2676 119028 140618 152942


3 Results



0

100

200

300

400

500

Num

ber o

f gla

cier

s

1970s20012013


Area (km2)












40

80

120

160

Num

ber o

f gla

cial

lake

s

1970s20012013

01-02

Area (km2)








5o193 72 11 37 19 4 15o194 15 0 0 8 4 35o196 55 15 31 8 1 05o197 36 2 3 11 9 115o198 76 8 23 21 20 4Total 254 36 94 67 38 19

4

2

3

101

121317

19

8 571815

10121317

8 5

11

7

1469

16

N

0 30000 60000

(m)


4027minus4644

4644minus5110

5110minus5678

5678minus8848





4 Discussion


1970s 2001 2013

(m)0

N

2500 5000

(a)

1970s 2001 2013(m)

0 2500 5000

N

(b)









0

05

1

15

1970 1980 1990 2000 2010

0

100

200

Year

Prec

ipita

tion

(mm

)


minus05

minus1

minus15 minus200

minus100

Tem

pera

ture

(∘C)




1970 1980 1990 2000 2010

5

8

11

14

17

Year

MayJuneJuly


Tem

pera

ture

(∘C)




5 Conclusion






Acknowledgments


References

















































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in







5o193 62 61 72 915 965 1013 541 1073 20054 22115 215545o194 16 15 15 708 794 747 1209 542 31399 35705 333375o196 37 36 55 935 991 1071 600 1453 28563 30668 313075o197 25 24 36 663 746 1139 1246 7184 17175 20586 333045o198 59 60 76 940 1215 1305 2922 3882 21837 31544 33440Total 199 196 254 4161 4709 5275 1318 2676 119028 140618 152942


3 Results



0

100

200

300

400

500

Num

ber o

f gla

cier

s

1970s20012013


Area (km2)












40

80

120

160

Num

ber o

f gla

cial

lake

s

1970s20012013

01-02

Area (km2)








5o193 72 11 37 19 4 15o194 15 0 0 8 4 35o196 55 15 31 8 1 05o197 36 2 3 11 9 115o198 76 8 23 21 20 4Total 254 36 94 67 38 19

4

2

3

101

121317

19

8 571815

10121317

8 5

11

7

1469

16

N

0 30000 60000

(m)


4027minus4644

4644minus5110

5110minus5678

5678minus8848





4 Discussion


1970s 2001 2013

(m)0

N

2500 5000

(a)

1970s 2001 2013(m)

0 2500 5000

N

(b)









0

05

1

15

1970 1980 1990 2000 2010

0

100

200

Year

Prec

ipita

tion

(mm

)


minus05

minus1

minus15 minus200

minus100

Tem

pera

ture

(∘C)




1970 1980 1990 2000 2010

5

8

11

14

17

Year

MayJuneJuly


Tem

pera

ture

(∘C)




5 Conclusion






Acknowledgments


References

















































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in










40

80

120

160

Num

ber o

f gla

cial

lake

s

1970s20012013

01-02

Area (km2)








5o193 72 11 37 19 4 15o194 15 0 0 8 4 35o196 55 15 31 8 1 05o197 36 2 3 11 9 115o198 76 8 23 21 20 4Total 254 36 94 67 38 19

4

2

3

101

121317

19

8 571815

10121317

8 5

11

7

1469

16

N

0 30000 60000

(m)


4027minus4644

4644minus5110

5110minus5678

5678minus8848





4 Discussion


1970s 2001 2013

(m)0

N

2500 5000

(a)

1970s 2001 2013(m)

0 2500 5000

N

(b)









0

05

1

15

1970 1980 1990 2000 2010

0

100

200

Year

Prec

ipita

tion

(mm

)


minus05

minus1

minus15 minus200

minus100

Tem

pera

ture

(∘C)




1970 1980 1990 2000 2010

5

8

11

14

17

Year

MayJuneJuly


Tem

pera

ture

(∘C)




5 Conclusion






Acknowledgments


References

















































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in




5o193 72 11 37 19 4 15o194 15 0 0 8 4 35o196 55 15 31 8 1 05o197 36 2 3 11 9 115o198 76 8 23 21 20 4Total 254 36 94 67 38 19

4

2

3

101

121317

19

8 571815

10121317

8 5

11

7

1469

16

N

0 30000 60000

(m)


4027minus4644

4644minus5110

5110minus5678

5678minus8848





4 Discussion


1970s 2001 2013

(m)0

N

2500 5000

(a)

1970s 2001 2013(m)

0 2500 5000

N

(b)









0

05

1

15

1970 1980 1990 2000 2010

0

100

200

Year

Prec

ipita

tion

(mm

)


minus05

minus1

minus15 minus200

minus100

Tem

pera

ture

(∘C)




1970 1980 1990 2000 2010

5

8

11

14

17

Year

MayJuneJuly


Tem

pera

ture

(∘C)




5 Conclusion






Acknowledgments


References

















































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in







0

05

1

15

1970 1980 1990 2000 2010

0

100

200

Year

Prec

ipita

tion

(mm

)


minus05

minus1

minus15 minus200

minus100

Tem

pera

ture

(∘C)




1970 1980 1990 2000 2010

5

8

11

14

17

Year

MayJuneJuly


Tem

pera

ture

(∘C)




5 Conclusion






Acknowledgments


References

















































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in


1970 1980 1990 2000 2010

5

8

11

14

17

Year

MayJuneJuly


Tem

pera

ture

(∘C)




5 Conclusion






Acknowledgments


References

















































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in










Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in

Documents

Research Article Changes in Glaciers and Glacial …downloads.hindawi.com/journals/amete/2014/903709.pdfResearch Article Changes in Glaciers and Glacial Lakes and the Identification