water resources in the himalayas - assesment and sustanability by rd singh

8/13/2019 Water Resources in the Himalayas - Assesment and Sustanability by RD Singh

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Terai 4600m

Outer Himalaya1500- 3500m

Tibetan Plateau

4000m

Western Disturbances

Nov. March/April

SW MonsoonJune Sep

Glaciers 10%

Winter snow cover 35-50 %

Maximum monsoon precipitation at

1500 3000 m asl


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Inaccessible & inhospitable mountainous conditions

Variation in altitude, slope, aspect, soil, and landuseHydro-meteorological characteristics change over shortdistances (say on windward and leeward sides)

Quite sparse hydrological network in various basins

Need for high density of hydrometric stations for reliableassessment of hydrological variablesIn addition, need for proper design of hydrometric

network and installation of automated telemetry stations


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Hydrological network and database

Impact of climate change on regional water resources

Changing glacial resources

Flash floods generated from Cloudburst/GLOF

Excessive soil erosion and siltation in river flows

Conservation & management of lakes & springs


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A number of high altitude natural lakes: Wular, Dal,

Nagin, Manasbal, Mansar, Surinsar and Sanasar etc.

These lakes are of high socio-economic importance butdeteriorating with time in quantity and qualityImportant to estimate water balance components of lakesand suggest measures for their preservation & sustenance

A large number of springs in mountainous areas whichserve as a source of water supply for nearby population

Water flows in the springs are diminishing with time. It isimportant to understand the hydrology of recharge zones

Depending on the causes of diminishing spring flows,

ameliorative measures needed to sustain spring flows


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Water resource potential in theHimalayan river basins - India

SI. No.Name of the River

Basin

Average AnnualPotential

of the River

BCM

1. Indus (up to Border) 73

2.

a.) Ganga 525

b.) Brahmaputra,

Barak & Others585


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Basin name Basin area,

km2

Glacier

area, km2

Glacier

area, %

Population,

106

Indus 1,139,814 20,325 1.78 211.28

Ganges 1,023,609 12,659 1.24 448.98

Brahmaputra 527,666 16,118 3.05 62.43

Himalayan River basins, Glacier cover & Population

NAP-2012


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GANGA BASIN

Uttarakhand

Glaciers- 968

Area- 2857km2

Avg.size3.87km2

NEPAL&BHUTAN3500 Glaciers

INDUS BASIN

J&K

Indus,Nubra,Shyok,Jhelum,Gilgit

Glaciers - 5253

Area 29163 km2

Avg.size 10.24 sq.km

H.P

Chenab,Beas,RaviSatluj Rivers

Glaciers 2786

Area 4466

Avg.Size 3.35km2

BRAHMAPUTRA BASIN

ARUNACHALKamang River

Glaciers 162

Area 228km2

Avg.Size 1.41 km2

SIKKIMTista River

Glaciers 449

Area 706 km2

Avg.Size 1.59km2

Total - 13075

India- 9575 glaciers (GSI)

Distribution of Glaciers in the Indian Himalaya

Indus : 8039 Glaciers

Area : 33629km2

Ganga : 968 Glaciers

Area : 2857 km2

Brahmaputra : 611 Glaciers

Area :934km2


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SNOW AND GLACIER MELT RUNOFF

IN DIFFERENT HIMALAYAN BASINS

Chenab River Akhnoor 49%

Satluj River Bhakra Dam 60%

(Indian part)

Ganga River Devprayag 30%

River Site Av. snow & glaciers

melt contribution to

annual flows


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Winter Snow

regime (Alpine)

Cold-Arid regime

Summer Monsoon +

Winter snow regime

(Himalayancatchment)

Chenab Basin

24N

28N

32N

36N

72E 80E 88E 96E

Climate & Hydrology vary across the Himalayas offering diverse

challengesGlacio-Hydrological regimes of the Himalaya

Thayyen & Gergan, 2010, The Cryosphere


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A) Alpine catchment (Indus Basin)

B) Himalayan catchment

(Ganga &Brahmaputra basins)

In winter snow dominated Alpinesystem, peak glacier runoff

contributes to other wise low flow

period of annual stream hydrograph

governed by lower precipitation in

summer. (Snow>Rain>Glacier)

Monsoon dominated Himalayan

catchment is characterized by the

peak glacier runoff contributing to

the crest of the annual streamflow hydrograph from monsoon in

July and August months.

(Rain>Snow>Glacier)

Variations in Temporal distribution of

precipitation ,glacier melt & stream

flow characterise various glacio-

hydrological regimes of the Himalaya

Thayyen & Gergan, The Cryosphere 2010


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C) Coldarid catchment (Indus Basin)

In the cold-arid regions of the

Ladakh, characteristics are similar

to that of Alpine system with

extremely low precipitation.

(Snow>Glacier>Rain)

Thayyen & Gergan, The Cryosphere 2010

Precipitation distribution of

various glacier basins of the

Himalaya


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Ganges & Brahmaputra, Indus (Sutlej & Beas)Indus basin

Indus basin

Precipitation variability (Snow &

Rain) from east to west & across

altitudes controls the hydrology of

mountains.


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HYDROLOGICALMODELLING


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Snow Melt Runoff Simulation Models

Snowmelt Module

Generates liquid water from thesnowpack that is available for runoff.

Transformation Module

Converts the liquid output at the groundsurface to runoff at the basin outlet.


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Lumped

Whole catchment as a single unit

Distributed These models account for thespatial variability

Lumped and Distributed models can befurther classified as

Energy balance Temperature index


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RAIN

DISTRIBUTION

OF RAIN

SNOW MELT

CONTRIBUTING

AREA

GLACIER MELT

CONTRIBUTING

AREA

GLACIER MELT + RAIN

+ RAIN MELT

SNOW MELT + RAIN

+ RAIN MELT

TOTAL GENERATED STREAM FLOW

DISTRIBUTION

OF SNOW

DIRECT SURFACE

RUN OFF FROM

SNOW COVERED AREA

DISTRIBUTION

OF TEMPERATURE

GLACIER AREASNOW COVER AREA

RAIN + RAIN MELT

INFILTRATION

ACCOUNTING

OF LOSSES

INFILTRATION INFILTRATION

ROUTING

BASEFLOW

Flow chart of the snowmelt model (SNOWMOD)

PRECIPITATION

FORM OF

PRECIPITATIONSNOW

ACCOUNTING

OF LOSSES

ACCOUNTING

OF LOSSESDIRECT SURFACE

RUN OFF FROM

GLACIER AREA

DIRECT SURFACE

RUN OFF FROM SNOW

GLCIER FREE AREA

RAIN OVER SNOW AND

GACIER FREE AREA

TEMPERATURE

ROUTINGROUTING ROUTING


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Division of a basin into elevation zones

Processing of meteorological data

temperature distribution

precipitation distribution

Form of precipitation

Depletion of snow covered area

Glacier extent and its exposing trends

Rain-induced melt

Accounting of losses

Routing of surface and subsurface flow

MODELLING OF SNOW AND GLACIERMELT RUNOFF


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Elevation of the study area varies from ~ 305 m to 7500m.

Mean elevation of the basin is about 3600 m.s.l.

Total catchment area up to Akhnoor is 22,200 sq km

Total Number of Glaciers is 989.

Glacierized Area is 2280 sq km.

Case study of Chenab Basin


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A comparison of observed and simulated discharge of the Chenab River at Salal Dam for the calibration

period (1996/1997 to 1998/1999).

0

2000

4000

6000

8000

Disc

harge(m3/s)

O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1996 1997 1998 1999

Observed discharge

Simulated discharge

Rainfall runoff

Melt runoff

Baseflow


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Model efficiency for the calibration period

(1996/1997, 1997/1998 and 1998/1999)

Period R2 Volume

difference (%)

1996/1997 0.87 7.07

1997/1998 0.94 0.98

1998/1999 0.86 9.91

1996/1997 to1998/1999

0.91 2.48


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A comparison of observed and simulated discharge of the Chenab River at Salal Dam for the vaidation period

(1999/2000 to 2001/2002).

0

1000

2000

3000

4000

Disch

arge(m3/s)

O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1999 2000 2001 2002

Observed discharge

Simulated discharge

Rainfall runoff

Melt runoff

Baseflow


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Model efficiency for the validation period

(1999/2000, 2000/2001 and 2001/2002)

Period R2 Volume

difference(%)

1999/2000 0.91 1.732000/2001 0.90 7.97

2001/2002 0.91 3.95

1999/2000 to

2001/2002

0.92 6.6


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GAUGING

SITEPAKISTAN

CHINA

BAY

OF

BENGAL

Figure: Location map of Gangotri Glacier

Case study of Gangotri Glacier


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DATALOGGER

AIR TEMPERATURE & RELEVENT HUMIDITY SENSOR

BAROMECTRIC PRESSURE SENSOR

WIND SPEED &DIRECTION SENSOR

ALBEDOMETER

ULTRASONIC SNOW DEPTH

NET PYRANOMETER

TIPPING BUCKET RAIN GAUGE

INFRA RED SNOW SURFACE TEMPERATURE SENSOR

Installation of AWS at Gangotri Glacier

250Observed flow2005

200Observed flow

Si l t d ff

2006


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Days

0

50

100

150

200

Discharge(m3/s)

Simulated runoff

Snowmelt runoff

Rainfall runoff

Baseflow

May June July Aug. Sept. Oct. Nov.Days

0

40

80

120

160

Discharge(m3/s)

Simulated runoff

Snowmelt runoff

Rainfall runoff

Baseflow

May June July Aug. Sept. Oct. Nov.

Days

0

40

80

120

160

Dischar

ge(m3/s)

Observed flow

Simulated runoff

Snowmelt runoff

Rainfall runoff

Baseflow

May June July Aug. Sept. Oct. Nov.

2007

Different components of simulated runoff for summer season (2005-2007) for the Gangotri Glacier.


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Percentage difference in volume, model efficiency and

contributions of rainfall, snow & glaciel melt and base flow

computed by the model.

Year Model Percentage

Diff. in

Vol.

Model

efficiency (%)

Rain

(%)

Snow

(%)

Base flow

(%)

2005 Snowmod -4.01 90 4.00 85.10 10.90

2006 Snowmod -1.61 95 2.06 86.34 11.60

2007 Snowmod 0.29 93 1.30 86.39 12.31


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Impact ofClimateChange

Temperatureincrease

Change inMonsoonPattern

Increase inRain FallIntensity

Decrease inNo. of Rainy

Days

Decrease inSnow Fall

Increase inGlacierretreat

Increase inEvaporation

rate

Change inRunoffPattern

Change in

Ground waterRecharge

Increase inExtremeEvents

Sea LevelRise

Change inwater quality


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Chhatru (Chenab)

Batal (Chenab)

Beaskund-2 (Beas)Beaskund-1 (Beas)

Volume - 49%

Area - 43%Recession 7.5 m/yr

Volume -7%

Area - 5%

Recession 26 m/yr

Volume -26%

Area - 22%

Recession 54m/yr

Volume - 48%

Area - 41%Recession 2 m/yr

1980

2006


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Phutse glacier

Khardug glacier

Nangtse glacier

Unnamed vanished glacier


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Region Area Change %

Alaknanda basin (1968-2006) -5.72%

Bhagirathi basin (1968-

2006)

-3.32%

Region Elevation

Range

Area

Change

%

Ladakh Range

(1973-2007)

5200- 5800 m

a.s.l.

-14.7

Kashmir &

Drass(1976-2006)

3600 5100 m

a.s.l.-14.0

Bambri et al

2011

Glacier Change in the Himalaya

NIH Study,

2010


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SAC ,Ahmedabad

1962 2004

Area-class

(km2)

Number Area

(km2)

Area

(km2)

Area

Change

(%)10 25 635 559 -12

Total 359 1414 1110 -21

Glacier change - Chenab basin


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Bhutiyani et al 2007

Variation of mean annual maximum (a), minimum (b) and mean

temperature (c) (STI values) in the northwestern Himalaya in the last

century. (Tmax=mean maximum temperature, Tmin=mean minimum

temperature, Tavg=mean annual temperature, Y=time in years)


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Decade-to-decade change in annual mean maximum, mean minimum and average

air temperatures (in C/year) in the last century. Positive (negative) values indicate

increasing (decreasing) temperatures. a Mean maximum b mean minimum c

annual average


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Increase in

diurnal

temperaturerange Western

Himalaya


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Seasonwise decade-to-decade rates of


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increase/decrease in standardized precipitation and

temperature indices (SPI and STI) in the NWH.(a) Winter, (b) Monsoon and (c) Annual.


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Satluj ChenabBeas

Varying trend in discharge of some Himalayan Rivers suggesting

non-uniform response of Himalayan rivers in various hydrological

regimes

Source: Bhutiyani et al


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L h l db t I t


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Leh cloudburst Impact areas

Thayyen et al 2012


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Cloudbursts and Flash floods in the Himalayas

Leh August 4 6 2010


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Site of GLOF washed out bridge

Site of GLOF washed out Road

Pond

sites


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Road washed off Flood mark on the banks of lake

Washed of Culvert enroute to Pangong Lake

S.No Basin No of Glacial Lakes


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1. Tons 12

2. Yamuna 8

3. Bhagirathi 30

4. Bhilangana 2

5. Mandakini 10

6. Alaknanda 43

7. Pinder 1

8. Goriganga 10

9. Dhauliganga 7

10. Kutiyangi 4

11. Beas 59

12. Chenab 33

13. Satluj 40

14. Ravi 17

15. Taklinga 7

16. Teesta 266


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Projecting Climate Change Impacts on Hydrology

Climate Change Projections

(precipitation, temperature,

radiation, humidity)

Topography, Land-

use Patterns; soil

characteristics;

Hydrologic Model

Possible Future Hydrologic

Scenarios on Basin Scale

(Streamflow, Evapotranspiration, Soil

Moisture, Infiltration, Groundwater

Downscaling


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Sustainability issues of Himalayan water

resources

Need to characterise the glaciers of different regions in Himalayas. Cotribution ofrainfall, snow melt, glacier melt and base flow to the stream flow may be estimatedfor different temporal and spatial scales using hydrologic modelling approach.

Climate change and its impact on these flow contributions are required to bescientifically investigated and adaptation strategies are suitably evolved forsustainability of flows in river system.

Lakes in the Himalayas are main source of drinking water and recreation in manyareas. For sustainability , lake water balance and lake water quality studies need tobe carried.

In many areas spring flows are drying. Scientific studies are required to investigatethe reasons for this phenomena. Suitable recharge zones need to be identifiedand springs are required to be rejuvenated through artificial recharge wherever it isfeasible. It would provide sustainability of spring flows in the long term.


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Glacier and snow-melt have major contribution to theriver flows in the region. It is necessary to characterizethe glaciers in different climatological regions of the basin

To develop adaptation strategies to cope up with the likelyclimate change impacts, it is important to carry out

hydrological modeling studies for different basins withprobable climate change scenarios

In view of the enormous hydropower potential in thebasin, plan should be developed to generate maximum

hydropower from the available resources

Sedimentation being a major concern for development ofnew projects, watershed prioritization measures may beadopted to control sediment generation & movement

water resources in the himalayas - assesment and sustanability by rd singh

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