Bu王IetinofGlac主erResearch15く1997）53一ふぎ ゑヲ ⑥DataCenterforGiaeierResearch，JapaneseSocietyofSnowand王ce

BasicstudiesforassessingtheimpactsoftheglobalwarmingontheHimaIayancryosphere， 1994－1996

MasayoshiNAKAWOl，KojiFUJITAl，YutakaAGETAl，KiranSHANKAR2，AdarshaP．F）OKHREL2 and YAO Tandong3 1InstitlユteforIiydrospberic¶ÅtmospbericScjerlCeS，Nagoyat7nまvers毎，Nagoya464－01Japa王】 2t）epartmentofHydroiogyandMete（）rOiogy，MinistryofScienceandTec王InOlogy，Kathman血，Nepa1 3LanzhouInstituteofGlaciologyandGeocryology，ChineseAcademyofSciences，Lanzhou，China

（ReceivedMarch26，1997；RevisedmanuscriptrcceivedAprilll，1997）

Abstract

Athree－yearprOjecthasbeencarriedouttoobtainbasicknowIcdgeforassessingtheimpactof therecentglobalwarmingontheHimalayas，Ofwhichmanyglaciersandpermafrostareconsidered VeryVulnerabletothewarming．ThefieldstudywasmadebothintheNepalHimalayasandthe TibetanPlatealま行om1994to1996underacollaboratio王1betveenJapanese，Nepa王eseandC壬Iinese SCientists．Itwasfoundthatmanyglaciersintheareawereshrinking．Detailedprocessofindivid・ ualglacierwasalsostudied，inparticularondebriscoveredglaciersforwhichthemeltingprocesshas been poorly understood so far．Many of wood and snow／ice samples have been collected for reconstructingtherecentclimatechangeoverthearea．

1．lntroduction meteorological process studies for assessing and predicting theimpact of the past and／or further TheHimalayancryosphereconstructedwithgla・ Changein climate on the cryosphere．The present Ciersandpermafrostisveryimportantinwatercirclユー report describes briefly the field investigations and Iationinthearea．ln Nepal．forexample，mOStOfthe introdtlCeSSOrneOftherestiits＄O far obtained． riversarenourishedbyglaciersintheHimalayasin particular during the dry season when the water 2．Observations demandisintense．Thecryosphere，however，isvery Vulnerable to the risein air temperature，and the Theinvest短ationswerecarriedoutinTanggula recentglobalwarmingcolユIdaffectsignifieantlythe MountainsandXixiabangmaareainTibetassbown presentrunoffregime．Itisi王npOrtant，漁erefore，tO irlFig．1，Vbere TG and XBindicate tbe two sites examinetherecentchangesofglaciers，meteOrOlogi－ respectively，ln Nepal，five sites were selected for Caland hydrologicalelements concerned，and to the studies：Khumbu（KB），Shorong（SH）， understandvarietyofprocessesamongthem． RoIwaling（RW），Langtang（LT）and Hidden A three－year prOject was elected and the field Valley（HV）．Theirlocations are shownin Fig．2， investigatiorlSCOnductedinNepaiHimaiayasandin WhereXixiabangrnainTibetisa王somarked． TanggⅥ1aMountains，CentralTibet，from1994to1996． The time sequence ofthe field observationsfor Thefieldactivityincludedthedetectionoftherecent thethreeyearsareshowninFig．3．Horizontalbars Change of glaciers（glacier monitoring），COntinuous indicate the rough time periods during which the data collection of meteorological elements at two abbreviatedstudysitesasshownabovewerevisited． Stations（oneinNepaland onein Tibet），WOOd and AWSinthefigureindicatesthevi＄itstoanautomatic S！10W／icesampiingforreconstructiI唱paStCliInatein Weather stationi‡1Stal王ed at Syambocbe，SOuthern the motlntains，and glaciologicai，hydrologicalandma‡嘗in of払e Kbumbtiare乱 Ånotber weatber sぬ－ カ■J Bulletin of Glacier Research

tionwasinstalledandmaintainedinTanggulamoun－ tains，butthevisitstothestation，inFig．3，areinclud－ edintheactivitiesinTanggula（TG），Participantsfor eaehfieldsitesinparticularperiodsarelistedinTable l，inⅥ㌢bic王IpeOpleforoniylogisticsupportareexciud－ ed．TheinvestigationsatRoIwalingweremadewith acollaborationwithWaterandEnergyCommission Secretariat（WECS），His Majesty’s Government Of Nepal，andacoupleofresearcherswerewithus，but their names arenotlisted either．

8m 9¢●E 3．Glacier fluctuations Fig．1Study area．TG：Tanggula Mountains；ⅩB： Ⅹixabangma． Themassbalanceandthesizeofglaciershave beenmeasured，Since1973，intbeHimalayas．Glacier AXOlOinS量10rOng，isoneofthewellstudiedglaciers amollgthosein（he Hil11；llayas（（．g．Agetaand Higu－ Chi，1984；AgetaandKadota，1992；KadotaandAgeta， 1992）．Theglacierwasselectedforfurthermonitor・ ing．TheRikhaSambaGlacierinHiddenValleyand theGyajoGlacierinKhumbuwerealsoselectedtobe monitored，Sincetheglaciersweresurveyed atleast once and the mass balance data were also obtained q 80 16 （Tanaka，1972；Fushimi，1978；Fq5iieial．，1976； Nakawo eiaL，1976），although they were not asin deとailas for Glacier AXOlO．The Yala Giacierin Lallgt；1ngWaSalsodecidedtobemonitored，Whichhas Fig．2 Stud）・Sitesin Nepal．1t＼：’：Hidden VaH町：LT： been s11rVeyedintemittentiy si王1Ce1981（Yokoyama， Langta叩こ RW：Roh・alingこ Stl：Sho［LOng；KB： 1984）．lnTibet，themassbalancestudywasstarted Khumbu；ⅩB：Ⅹixabangma． in1989andin1991attheXiaoDongkemadiGlacierin Tanggula（Sekoetalり1994；PuandYao，1994；Fujita et al．，1996）and Kangwure Glacierin Xixiabangma

萱 Apr． Mav Jl∫1e …Jl加 Al鳳 Sep． Ocし （Liuet al．，1996）respectively，andthestudyhasbeen COntinuedinthisproject． T（3 蜃 ＄H， ㈹ xe f Inthosestudiesofmassbalance，alltheglaciers RW Were found to have decreased signi缶cantlyin their H totalmass．The decreasing rate was very highin COmparedwithglaciersintheotheLTpartOftheworld． Ådditio‡lally，in GlacierAX810，也e幻owspeed was found to have decT・t）aSedlately．which eould be eor－ related with the decreasein mass balance．The detailedresultswi11bepublishedelsewhere． The above six glaciers selected for monitoring arerough1ydebrisfreeattheirsurfacesandrelatively Fig．3 Time series of fieldinvestigations．AW S：Auto・ Smal1in size．In NepalHimalayas，however，1arge maticWeatherStationatSyamboche，Abbreviations glaciersaremostlycoveredwiththick debrisatthe forthestudysitesaregiveninFigs．1and2． surfacesinthe ablation area．Itwasexpectedthat the debris covered glaciersⅥ701ユ1d respond to the climate changein a different way from the sn－all glaciers．Additionaltwoglaciers（KhumbuGlacierin Nakawo ggβJ． 反ざ

Tablel．Thelistofparticipantsinthefieldobservations． Researcbsite Mont壬1S：Members 1994 Ta王igguia 5 Ftljitaユ，Gao2，Hou2，Ka喝2，Ma2，NakawoIPu2，Sun2，Ⅹiao2，Yabtlkiま，Zbang宣 Roまwali王唱 5←6 K野aStha8，Sakaiヰ，Takeuchi5，Yamadaヰ，（ⅥrECS） Ⅹixabanama 6 Fujital，Liu2，Pu2，Sun2，Yabl沈il，Yao2，Zhang2 Langtang 7－9 Fujital，Kayastha3，Takeuchi5，Sekol，Yoshimura5 Shorong 9－10 Kakastha3，Kubota6，Suzuki7，Ueno8 AWS 10 Kayastha3，Kubota6，SljZuki7，Ueno8 HiddenValley 1（l Fujii9．FujitaL．Paud）lal1

1995 RoIwaling 4－5 Fujital，Kadota1 Khumbu 4－5 Aoki（Te）10，Aryal3，Sekol，Yoshimura5 AWS 5 Aoki（Te）10Aryal13，Iidall，Sekol，Yoshimura5 Tanggula 5－6 Leng2，Pu2，Sekol，Wang2，Yoshimura5，Zhang2 RoIwaling 5 Chikita12，Sakail，（WECS） Langtang 6 Koji王na7，Kubota8，Naitol，Nakawol，Ra11a1 Shorong 6 F房itaユ，Kadotal，Yadav3 Shorong 10 Fujital，Kayastha3，Sakail，Takeuchi5，Yamaguchi4 AWS 10 Sekol，Yabukil Khumbu lO－11Aoki（Ta）13，Arya13，Fujital，Fushimi14，Iwata15，Kadotal，Kayastha3，KohshimaS， Sakail，Sekol，Takeuchi5，Yabukil，Yamaguchi4

1996 Langtailg 5－10 Adbikaryl，Aoki（Ta〉13，Aoki（Te）10，Åsabi15，Battl，Cbettri3，Fujital，Kayastbaき， Kubota6，Masuzawal，Misbra3，Nakawol，00isbi＄，Ranal，Sakaii，Sbakya3，Swedal＄， Takeuchi5 AWS 5 Ueno14，Fujinami8，Kayastha3 AWS 8 Kayastha3，Pokhare13 Shorong 10 Agetal，Kadotal，Kayastha3 Khumbu 11 Kadotal AWS ll Xa（璽otai Affiiiations：1．Institute for Hydrospheric－Atmospheric Sciences，Nagoya University．2．LanzhouInstitute of Glaciology and GeocryoIogy．3．Departmentof‡iydrologyandMeteorology．4．InstituteofLowTemperatureScience，HokkaidoUniversity．5．Tokyo InstituteofTechnology，6．TokyoUniversityofAgricultureandTechnology．7．IwateUniversity．8．TsukubaUrliversity．9．National Institute of Polar Research∴川．MeteorologicalResearchInstitute．1l．Toyama PrefecturalGovernment．12．Faculty of Science， HokkaidoUniversity．13，TheUniversityofTokyo．14．TheUniversityofShigaPrefecture．15．TokyoMetropolitanUniversity．16． SchooiofAgrict】主知re∴Nagoyat7niversity，

KhumbuandLirungGlacierinLangtang）withsupra measuredin Khumbu，Hidden Va11ey，Shorong and rglacialdebris were selected，therefore，tO be Langtang，and examined with published mapsin examinedin the recent changein their totalmass HonguregionnearKhumbuduringthepresentthree Si11CetbeyⅥrereSt汀Veyedin1978aIld1987respectiveiy 鵬year prOject．‡t was follnd tbat tbe terminihave （Iwata gぎα乙，1980；Yamada g≠αgリ199礼 Detailed basicallyretreatedandnog王acier appeared to bave mapplng Of the glaciers disclosed the significant advanced． decrease oftheir mass（thinning）after the previous In additionto theglacierchange，the change of SurveyA permafrost was also studied by detectingitslower The response of glaeiers to the climate change limitin Hidden Valley and Khumbu，Sinceit was Canaisobedetectedbyobservingthecbangeinとermi－ Observedin1970s（ぎujiiandHigucbi，19発）． ntlS pOSi七重on of glaciers，altholjgb the dynamics of individualglacierhastobetakenintoaccountforthe 4、Automatjcweatherstations（AWS） quantitativeassessment．Sincetheterminusposition isarathereasymeasureofestimatingglaciermass， ln the mountainous areain the centralpart of datahavebeenpiiedupatieast主ntheareaschosenfor Asia，therearefewmeteorologicalstations．Inthis the presentprojeでt tLl．g．Fushimiand Ohata，19占0； prqject，tiierefore，Wemadeanefforttoestablisband Yamada et al．，1992）．The terminus position was maintaintwoautomaticmeteorologlCalstationsinthe 56 Bulletin of Glacier Research

Studyarea．OnestationwasestablishedatSyambo－5．Samp‖ngofwoodandsnow／ice Che，Khumbu，Nepalin1994．Themeasuredcompo－ nents at the station arelistedin Tables2，and they To examine the response of glaciers to the cli－ havebeenmeasuredevery30minutes．Anotherwas mate change，itis essentialto know the recent preparedatTanggulaMountains，China，Wheresimi－ reglOnalclimatechangeoverthearea．InthemounT larobservationhadbeencarriedoutalready（Ohataet tains，however，aSmentionedintheprevioussection， al．，1994）．The previous station was modified，ren－ instrumentalrecordoftheclimateisratherpoor．In ewed andre－arrangedin1994andmaintained after－ thepresentstudy，therefore，Weplannedtoreconstruct wards．The basic elements were the same as the the recent climate change with proxy data through previous observation．Table3shows the observed dendro－ChronologlCalanalysisandicecore analysis． elementsattheTanggulastation，Wherethedatahave Atotalof188incrementcoresoftree－ringrepresentT beencollectedeverylhour．Thebothstationshave ing94individualtreesweresampledfrom4studysites WOrkedsatisfactorily（Uenoetal．，1996），andweplan inLangtangValley，Nepal，andasnow／icecoreof23 tocontinuetheobservationfurtherbeyond1997． minlengthattheaccumulationareaofRikhaSamba

Table2．SyambocheAutomaticWeatherStation Channel Element Sensors CataloRue accuracy Manufacturer Wind speed 3－Cup anemOmeter 2％ AanderaaCo．（2740） Wind direction Potentiometer type 5O same（3150） Relative humidity Hygrophiber 3％ same（2820） Downward shortwave Temperaturedifferencetype 2mW／cm2 same（2770） radiation （0．3－2．5JJm） Pressure Silicon chip 0．2hpa same（2810） Soiltemperature（15cm） Platinum resistor Air temperature Platinum resister 0，10C same（2775） Downward a11wave radiation Temperturedifferencetype 3％ same（2811） （0．3－60JJm） Upwardshortwaveradiation Temperaturedifferencetype 2mW／cm2 same（2770） Soiltemperature（0．5cm） Platinum resister Rain gauge Tippingbuckettype 0．5mm Net radiation Temperature difference REBS（Q＊7） （0．2560／‘m） Snow depth Supersonic 1mm KeyenceCO．（UD320）

Table3．TanggulaAutomaticWeatherStation Channel Element Sensor Catalogueaccuracy Manufacturer GroundTemperature（Ocm） Platinum resister 0．10C AanderaaCo．（2812） Wind speed 3－Cup anemOmeter 2％ AanderaaCo．（2740） Wind Direction Potentiometer 50 AanderaaCo．（3150） GlobalRadiation Temperaturedifferencetype 20W／m2 AanderaaCo．（2770） （0．3－2．5／Jm） AtmosphericRadiation Temperaturedifferencetype 40W／m2 AanderaaCo．（2811） （0．360JJm） ∫ GroundTemperature（5cm） Platinum resister ％ C AanderaaCo．（2812） ∫ Relative Humidity Hygroscopic hair ∫ AanderaaCo．（2820） C 0 Air Temperature Platinum resister AanderaaCo．（2740） 3 Ground Platinum resister C AanderaaCo．（2812） 0

Temperature（20cm） 0 ／ ハ GlobalRadiation Temperaturedifferencetype 2 W 肝 AanderaaCo．（2770）

（0．25－6叫m） O

Atmospheric Radiation Temperaturedifferencetype 40W／m2 AanderaaCo．（2811） （0．3－60／Jm） N；lka＼＼†いlイ〟／． 5ア

Glacier，Hidden Valley．Nepal（Fujiit7t aI．，199軋 One type Seemed to havelinked with the englacial Thesnow／icecoreisconsideredtocoverthelast90 hydrologicalsystem，andtheothertypebeingindepen－ years，based on a preliminary anaiysis of Tritium dentindividually without any water ehannelcon－ content．Thesamplesareunderexaminationandthe nected withthe otherlakesnorstreams．ThedifferT reslユ1tswillbereportedelsewhere． encecouldleadto differenteffectorcontribtltionto themeltingprocessfordebris－COVeredglaciers． 6．Dめris－COVeredglaci¢rS Chemical balance for Lirung Glacier was also examinedtakingintoaccountthechemicalconstitu－ Most oflargeglaciersin NepalHimalayas are entsin precipitation，englacial and supraglacial eovered with debris at their ablation area．The StreamS，iakes，giacierice，andrunoffvater． meltingprocessofthistypeofglaciershadnotbeen veilstudied except a few works（g．＆Inoue and 7．Hモatbudgetobservations Yoshida，1980），and even the rate of melting at the glacier surface was rather difficult to estimate Torelatetheglacierchangewiththeclimate，the becauseofthepresenceofdd）ris．Theprocesshas heatbudgetstudyisofgreatimportance．Duringthe beenintensivelyexaminedwithirlthepresentproject． present project，heat exchange between the atmo－ The ablation rate was estimated，for Lirung Spbere，glacier sudaces and soilsl汀ねces vas aiso GlacierinLangtang，withanenergymodelfordebris investigated．Solar radiationis the principalheat cover（Nakawo and Takabashi，1982），and tbe esti－ source for glacier ablatio11i11the Himalayas． matewascombinedwithahydrologicalmodel（Fukひ Detailed observations were hence made on how the shima，1988）tocalcuiate軌ediscbargefromtbegla－ radiationis absorbedin snow／icewith respect to cier．The estimation was compatible with the dis・ varietyofsnow／icetypessuchasparticle size，dust charge observation，indicating that the developed contentandsoonforrespectivewavelengths．Sig－ metbodcanbeusedforderiving也eablationrateat nificantcontributionofiongwaveradiationfromthe debris－COVeredglaciersandrunofffromthoseglaciers steep valley wall（including the reflection）was （Ra11all（L）［‥1997）．ThemethodL：OuldbefurtllerUSed identified．AIso，しhe characteristics of wind and topredicttheablation／dischargefordifferentclimatic moisture movement（including evaporation）were eonditionssuchaswithdoublingCO：（Rana，1997）．Itinvestigated in Langtang Valley for assessing the wasfoundalsothattheshrinkageofthedebrisLCOVA watercirculation，andaccordinglytheheatbudgetin eredglaciercontributedsignificantlytotheriverflow thebasinscale． andtheannualamountofdischargewasmuchlarger thantheannualprecipitation． A¢knowledgments Manysupraglaciailakesbavebeenfo11nd（）Ver払e debrispcovered area of manylarge glaciers．The WewouldliketoexpressoursirlCeregratitudeto PreSenCeOfthelakescouldplayanimporta11trOlein Ministr）・OfWilterResourcesandNationalCouncilfor the melting or the deterioration process of the glaN Science and Technology，HisMajesty’s Government ciers．TshoRolpaLakeneartbeterminusofTram－ ofNepal，andChineseAcademyofSciencesforthe bauGiacierseemedtobeakindoffinalstageofthe SpeCialconsiderationtothisprojectwiththepermis－ Supraglaciallakes，andtheheatbudgetobservations sionfortheresearch．WaterandEnergyCommission weremadeatthelake．Thelake wasconsidered to Secretariat，MWR，HMGofNepal，inparticular，has be one of the most dangerous glacier lakes which SuppOrtedusinthefieldinvestigationsinRoIwaling・ could caust？Gtacier Lake OtltbtlrSt FIood（Yal11ada． Mr，Om Bajrachar〉：a and the other many sIaffs of 1993）．Water and Energy Commission Secretariat Department of Hydrology and Meteorology have （WECS）wasalso主nterestedinthelakefromtheview supportedusduringthepreparationstageaswellasin pointofdisasterprevention，andthefieldinvestigaq the field workin Nepal．AIso，We have received a tions were carried out jointly with members from number of hearty stlppOrt from many staffs from WECS．Thes11praglacia‖akeswerestudiednotonlyLanzhouInstitute of Glaciology and Geocryology， atTrambauGlacierbutalsoatKhumbuGlacierand Embassy ofJaparlin Kathmandu，Kathmandu Club LirungGlacier．Itwasfound，byexaminingtbethree House．Guide for AllSeasL）nS Co．Ltd．TheiT kind glaciers，thattherecanbetwotypesoflakes，Ofwhich helps to our project are greatly appreciated．Our 5β Bulletin of Glacier Research

thanksareduetofriendlycooperationofmanylocal 16．OhataT．，K．Ueno，N．EndohandY．Zhang（1994）：Meteoro－ peopleinthefield，Withoutwhichourworkwouldnot loglCalobservationsin the Tanggula Mountains， Qingzang（Tibet）Plateau from1989to1993．Bulletin of havebeenpossible． GlacierResearch，12，77－86． Theexpenseofthisprojectwassupportedbya 17．Pu，J．andT．Yao（1994）：Massbalanceofglaciersinthe Grant－inLAid forInternationalScientific Research East Kunlun and Tanggula Mountains，Tibetan Plateau． Program（ProjectNo．06041051）fromtheMinistryof BulletinofGlacierResearch，12，105－107． 18．Rana，B．（1997）：Study on glacier ablation under debris Education，Science，Sports and Culture，Japanese －COVer for nlnOff modeling of a river basinin Langtang Government． Valley，NepalHimalaya．PhDthesis，NagoyaUniversity． 19．Rana，B．，M．Nakawo，Y．FuknshimaandY．Ageta（1997）： Re一台rences Application of a conceptualpreclpitation－runOff model （HYCYMODEL）inthedebrisTCOVeredglacierizedbasinof LangtangValley，NepalHimalaya．AnnalsofGlaciology， l．Ageta，Y．andK．Higuchi（1984）：Estimationofmassbalー 25，inpress． ancecomponentsofasummer－aCCumulationtypeglacierin 20．Seko，K．，J．Pu，K．FujitaりY．Ageta，T．OhataandT．Yao theNepalHimalaya．GeografiskaAnnaler，66A，249－255． （1994）：Glaciologicalobservationsinthe Tanggula Mts．， 2．Ageta，Y．andT．Kadota（1992）：Predictionsofchangesof TibetanPlateau．BulletinofGlacierResearch，12，57－67． glaciermassbalanceintheNepalHimalayaandTibetan 21．TanakaH．（1972）：Onpreferredorientationofglacierand Plateau：aCaSeStudyofairtemperatureincreaseforthree experimenta11y deformedice．Journalofthe Geological glaciers．AnnalsofGlaciology，16，89－94． SocietyofJapan，78，659－675． 3．Fujii，Y．andK．Higuchi（1976）：Groundtemperatureandits 22．Ueno，KリH．Iida，H．Yabuki，K．Seko，A．Sakai，G．S． relationtopermafrostoccurrencesintheKhumburegion Lhakupa，R．B．Kayastha，A．P．pokhrel，M．L．Shrestha，T． andHiddenVal1ey．Seppyo，38，SpecialIssue，125－128． YasunariandM．Nakawo（1996）：EstablishmentoftheGEN 4．Fujii，Y．，M．Nakawo and M．L．Shrestha（1976）：Mass automaticweatherstation（AWS）inKhumburegion，Nepal balanCe Studies ofthe glaciersin Hidden Valley，Mukut Himalayas．BulletinofGlacierResearch，14，13r22． Himal．Seppyo，38，SpecialIssue，17－21． 23．YamadaT．，T．Shiraiwa，H．Iida，T．Kadota，T．Watanabe， 5．Fujii，Y．，K．Fujita and P．Paudyal（1996）：Glaciological B．Rana，Y．AgetaandH．Fushimi（1992）：Fluctuationsof researchinHiddenValley，MukutHimalin1994．Bulletinof theglaciersfromthe1970sto1989intheKhumbu，Shorong GlacierResearch，14，7－11． andLangtangregions，NepalHimalayas．BulletinofGla－ 6．Fujita，K．，K．Seko，Y．Ageta，J．Pu and T．Yao（1996）： cierResearch，10，11－19． SuperimposediceinglaciermassbalanceontheTibetan 24．Yamada，T．（1993）：Glacierlakesandtheiroutburstfloods Plateau．JournalofGlaciology，42，454－460． inthe NepalHimalaya．Publishedby Water and Energy 7．Fukushima，Y．（1988）：Amodelofriverflowforecastingfor CommissionSecretariat，pp，37． asmallforestedmountaincatchment．HydrologicalProces－ 25．Yokoyama，K．（1984）：Ground photogrammetry of Yala ses，2，167－185． Glacier，LangtangHimal，NepalHimalaya．GlacialStudies 8．Fushimi，H．（1978）：Stratigraphic studies ofthe Gyajo inLangtangVal1ey，ReportoftheGlacier Boring Project Glacier，KhumbuHimal．Seppyo，40，SpecialIssue，17－20． 1981－82inthe NepalHimalaya，published bythe Data 9．Fushirni，H．andT．Ohata（1980）：Fluctuationsofglaciers CenterforGlacierResearch，JapaneseSocietyofSnowand from1970to1978inthe Khumbu Himal，East Nepal，Se－ Ice，99－105． ppyo，41，SpecialIssue，71－81， 10．Inoue，）．and M．Yoshida（1980）：Ablation and heat exchange overthe Khumbu Glacier．Seppyo，41，Special Issue，26－33． 1l．Iwata，S．，0．Watanabe and H．Fushimi（1980）：Surface morphologyinthe ablation area ofthe Khumbu Glacier． Seppyo，41，SpecialIssue，9r17． 12．Kadota，T．and Y．Ageta（1992）：Ontherelationbetween climate and retreat of Glacier AXOlOin the Nepal Himalayafrom1978to1989．Bul1etinofGlacierResearch， 10，1－10． 13．Liu，S．，Z．Xie，G．Song，L．，MaandY．Ageta（1996）：Mass balanceofKangwure（flattop）Glacieronthenorthsideof Mt．Xixiabangma，China．BulletinofGlacierResearch，14， 37－43． 14．Nakawo M．，Y．FujiiandM．L．Shrestha（1976）：Flow of glaciersinHiddenVa11ey，MukutHimal，Seppyo，38，Spe－ CialIssue，39－43． 15．Nakawo，M．andS．Takahashi（1982）：Asimplifiedmodel forestimatingglacierablationunderadebrislayer．IAHS PublicationNo，138，137－145．