Anup Saikia Pankaj Thapa Editors Environmental Change in the Himalayan Region Twelve Case Studies Environmental Change in the Himalayan Region Anup Saikia Pankaj Thapa (cid:129) Editors Environmental Change in the Himalayan Region Twelve Case Studies 123 Editors Anup Saikia PankajThapa Department ofGeography Department ofGeography &Planning Gauhati University SherubtseCollege, RoyalUniversity of Guwahati, India Bhutan Kanglung,Bhutan ISBN978-3-030-03361-3 ISBN978-3-030-03362-0 (eBook) https://doi.org/10.1007/978-3-030-03362-0 LibraryofCongressControlNumber:2018966394 ©SpringerNatureSwitzerlandAG2019 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpart of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission orinformationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilar methodologynowknownorhereafterdeveloped. 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ThisSpringerimprintispublishedbytheregisteredcompanySpringerNatureSwitzerlandAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Contents Snow and Ice Melt Contribution in the Daily Discharge of Langtang and Modi Rivers, Nepal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Rijan Bhakta Kayastha and Ahuti Shrestha Status of Climate Change and Implications to Ecology and Community Livelihoods in the Bhutan Himalaya . . . . . . . . . . . . . . 23 Andreas Hoy and Om Katel The Assessment of Deforestation, Forest Degradation, and Carbon Release in Myanmar 2000–2010. . . . . . . . . . . . . . . . . . . . . 47 Chuyuan Wang, Soe W. Myint and Maya Hutchins Climate and Remotely Sensed Markers of Glacier Changes in the Himalaya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Lydia Sam, Rajesh Kumar and Anshuman Bhardwaj Shrinking Glaciers of the Himachal Himalaya: A Critical Review. . . . . 89 Pritam Chand, Milap Chand Sharma, Ujjal Deka Baruah, Sanjay Deswal, Syed Umer Latief, Rakesh Saini, Parvendra Kumar, Satya Prakash and Pawan Kumar Analysing Geospatial Techniques for Land Degradation Studies in Hindu Kush-Himalaya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Anshuman Bhardwaj, Rajesh Kumar and Lydia Sam UrbanizationInducedLandUse-LandCoverChangesintheManipur Valley and Surrounding Hills: A Landscape Metrics Approach. . . . . . . 137 Kiran Sharma The Heat is on in the Himalayas: Assessing Srinagar’s Urban Heat Island Effect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Chandra Kant Pawe v vi Contents Swelter in the City: Population Distribution, Land Use Change and the Urban Heat Island Effect in Shillong, India . . . . . . . . . . . . . . . 173 Rashima Kachari A Socio-Economic Analysis of Livelihood Strategies in Agriculture Dependent Communities of Mizoram, India. . . . . . . . . . . . . . . . . . . . . . 189 Vishwambhar Prasad Sati Dairy Farming in the Eastern Himalayan Foothills: Perspectives from the Lower Dibang Valley, India. . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Puspa Komor Snow Cover Changes Observed Over Sikkim Himalaya . . . . . . . . . . . . 219 Smriti Basnett and Anil V. Kulkarni Snow and Ice Melt Contribution in the Daily Discharge of Langtang and Modi Rivers, Nepal RijanBhaktaKayasthaandAhutiShrestha 1 Introduction The Himalayan region acts as an active reservoir contributing significantly to the hydrology of the perennial rivers of South Asia including Nepal, supporting the livelihood of the people living in these areas. It stores more snow and ice than anywhere else in the world outside the poles and encompasses the Hindu Kush mountainsandtheTibetanPlateau(Bajracharyaetal.2014).Thusitisconsidered asthe‘watertowersofAsia’.Thehydrologicprocessesoftheseareasaredominated bythesnowandglacialmeltswhicharepredominantlyinfluencedbythechangein patternsofprecipitationandsurfacetemperature. The ability of glacio-hydrologic models to incorporate projected variations in climaticvariables,snowfallandsnowmeltalgorithms,groundwaterfluctuationsand soil moisture characteristics makes them especially attractive for water resources studiestowardsclimaticchanges(SinghandKumar1997).Moreover,suchmodels can be combined with plausible hypothetical climate change scenarios to generate information on water resource implications of future climatic changes. Therefore, manystudieshavebeencarriedoutintheHKHregionrecentlyusingdifferentglacio- hydrologicalmodels(Kayasthaetal.2005;AlfordandArmstrong2010;Immerzeel etal.2010;Pradhanangaetal.2014;Brownetal.2014;Bocchiolaetal.2015).The recentwarmingandincreaseinprecipitationvariabilityarelikelytocontributetothe increasedvariabilityofriverdischargeresultingintheinitialincreaseindischargeas glaciersmeltandthendecreaseasde-glaciationprogresses(JiménezCisnerosetal. 2014). Hence, it is important to assess the hydrological response to the changing climateusingappropriatehydrologicalmodellingmethodologiesinordertoestimate thefuturewatersupply.Thelatteraffectsthepopulationlivingdownstreamwhorely B R.B.Kayastha( )·A.Shrestha DepartmentofEnvironmentalScienceandEngineering,SchoolofScience,Himalayan Cryosphere,ClimateandDisasterResearchCenter(HiCCDRC),KathmanduUniversity, Dhulikhel,P.O.Box6250,Kathmandu,Nepal e-mail:[email protected] ©SpringerNatureSwitzerlandAG2019 1 A.SaikiaandP.Thapa(eds.),EnvironmentalChangeintheHimalayanRegion, https://doi.org/10.1007/978-3-030-03362-0_1 2 R.B.KayasthaandA.Shrestha on water from glacier and snow melt particularly during the dry season. Several empiricalrelationssuchasablationgradientandsnowmeltestimation(Racoviteanu et al. 2013), critical air temperature (Sharma et al. 2000), and degree day factor (Immerzeel et al. 2010) have been formulated to estimate the snow and ice melt contributionoftheHimalayanglaciers. Inthisstudy,amodifiedPositiveDegreeDay(PDD)modelisusedtoestimatedaily dischargefromthepartlydebriscoveredglacierizedLangtangandModiRiverbasins ofNepal.Thismodelisbasedontherelationthatthemeltingofsnoworiceduringany particularperiodisproportionaltothepositivedegree-day.Thepositivedegreeday factorinvolvesasimplificationofcomplexprocessesthataremoreproperlydescribed bytheenergy balance of theglacier surfaceand overlaying atmospheric boundary layer (Braithwaite and Olesen 1989). This approach is appropriate in regions with scarcedataasitrequireslessinputdataandusesasimpleequationtoestimatemelt (Kayasthaetal.2000a;Hock2003).Hence,inthepresentstudy,thePDDmodel,as usedbyKayasthaetal.(2005)andPradhanangaetal.(2014)fortheestimationof monthlysnowandicemeltfromtheglacierizedbasinhasbeenmodifiedtoestimate thedailysnowandicemeltanddailydischargefromthesetwobasinsandalsoproject futurebasindischargeswithrelativecontributionoftherunoffcomponents. 2 StudyArea ThisstudycomprisesoftwoglacerizedriverbasinsofNepal.TheLangtangRiver basinislocatedintheLangtangvalleyofRasuwadistrictofcentralNepal.Itisthe headwater area of the Trisuli River in the Narayani River system. The total area of the Langtang River basin is 353.6 km2 with elevation ranging from 3,652 to 7,215ma.s.l.basedontheAdvancedSpaceborneThermalEmissionandReflection Radiometer(ASTER)DigitalElevationModel(DEM)2009.Outofthetotalarea, 39% (137.5 km2) of the basin is covered by glaciers (debris covered and clean ice) and the remaining 61% (216.1 km2) by rock and vegetation (Fig. 1) based onICIMODGlacierInventory(2010).LandsatThematicMapper5(TM5)images from 23 January 2009 were used to delineate debris covered and clean glaciers fromthetotalglacierarea.Themeanannualtemperatureandprecipitationrecorded at Langtang Meteorological Station (LaMS), Kyangjing, Rasuwa district located withinthisbasinatanelevation3862ma.s.l.fortheperiod1988–2013were3.4°C and 686.9 mm, respectively (Department of Hydrology and Meteorology, DHM; GovernmentofNepal,GoN). TheModiRiverbasinislocatedintheAnnapurnaregionandhasatotalareaof 643.2 km2 with an elevation ranging from 757 to 8000 m a.s.l. based on ASTER DEM(2011).12%(77.5km2)ofthetotalareaiscoveredbyglaciers(debriscovered andcleanice)andtheremaining88%(565.6km2)isrockandvegetation(Fig.1), basedonRandolphGlacierInventory4.0(2014).Theannualmeantemperatureand precipitationrecordedattheLumleMeteorologicalStation(LuMS),Lumle,Kaski SnowandIceMeltContributionintheDailyDischarge… 3 Fig.1 LocationmapofLangtangandModiRiverbasinsinNepal districtatanelevation of1740 ma.s.l.withinthisbasinfortheperiod 1991–2009 were16.1°Cand5613.9mm,respectively(DHM,GoN). Outofthetotalarea,theLangtangRiverbasincontainsarelativelylargerpercent- ageofglaciercoverthantheModiRiverbasin(Fig.2).Inbothbasins,riverdischarge is maximum in July and August (mid-monsoon) due to the monsoon precipitation and the glacial melt during these months; whereas during the winter season, dis- chargeischaracterizedbyaconstantbaseflowwithnegligibleinflowsofrainwater andmeltwater. 3 ModelDescriptionandSetup ThePDDmodelisasimplemodelwhichestimatessnowandicemeltfromthedebris freeareasaswellasicemeltunderdebrislayerswithaminimumfielddatarequire- ment(Kayasthaetal.2005).InthisstudythemodifiedPDDmodelsimulatesdaily dischargefromthestudybasinsandestimatesthesnowandicemeltcontribution. Theentirestudybasinisdividedinto36elevationzonesinbothriverbasinswith azonewidthof100mforLangtangRiverbasinand200mforModiRiverbasin. Temperature and precipitation at each elevation zone of the Langtang River basin 4 R.B.KayasthaandA.Shrestha (a) 7150 Debris covered glacier Clean glacier 6650 Rock and vegetation ) 6150 s.l. a. m 5650 ( n tio 5150 a v e El 4650 4150 3650 0 4 8 12 16 20 24 28 Area (km2) (b) 7900 Debris covered glacier 6900 Clean glacier Rock and Vegetation s.l.) 5900 a. m 4900 ( n o ti 3900 a v e El 2900 1900 900 0 10 20 30 40 50 Area (km2) Fig.2 HypsographofaLangtangRiverbasinandbModiRiverbasin was obtained by using the temperature lapse rate of 0.59 °C/100 m (Pradhananga etal.2014)andprecipitationgradients(asgiveninEqs.1and2)wereappliedtothe temperatureandprecipitationfromtheLaMS. P (cid:2)P {1+0.0003(z−4000)} 4000m≤z ≤5000m (Seko1987) (1) z BH P (cid:2)1.39P z >5000m (Pradhanangaetal.2014) (2) z z