Impact of Climate Change on Water Resourcesof Nepal and Role of WECS

Gautam Rajkarnikar
Project Coordinator, Koshi River Basin Management Program

Water and Energy Commission Secretariat
Government of Nepal

E mail: pinku_gautam@hotmail.com
WEPA Dialogue in Nepal
14 December 2010
Kathmanu, Nepal

Outlines of Presentation• Brief Introduction of Water and Energy Commission
Secretariat ( WECS )• Country background• Water sector Scenario• Temperature and Precipitation Trend• Glacier Scenario• Case study• Result• Conclusion

Water and Energy Commission (WEC) and its
Secretariat (WECS)• The Water and Energy Commission (WEC) was established byGovt.of Nepal in 1975 with the objective of developing thewater and energy resources in an integrated and acceleratedmanner. Consequently, a permanent secretariat of WEC wasestablished in 1981 and was given the name, Water andEnergy Commission Secretariat (WECS).
• The primary responsibility of WECS is to assist Govt. of Nepal,
the Ministry of Energy and other related agencies in theformulation of policies and planning of projects in the waterand energy resources sector. This also works as central waterplanning unit of Govt.of Nepal. The objectives and mandatesof WEC and WECS have been revised and modified a numberof times since their establishment.

Composition of Water and Energy Commission
The composition of the Water and Energy Commission is as follows:• Minister for Energy - Chairperson• Members• Member, National Planning Commission(Water Resources)
Secretary, Ministry of Water Resources• Secretary, Ministry of Finance• Secretary, Ministry of Physical Planning and Works• Secretary, Ministry of Industry• Secretary, Ministry of Commerce and Supplies• Secretary, Ministry of Law, Jusice and Parliamentary Affairs• Secretary, Ministry of Agriculture and Cooperative• Secretary, Ministry of Foreign Affairs - Member• Secretary, Ministry of Environment• Secretary , Ministry of Science and Technology

Composition of Water and Energy CommissionContd..
• Secretary, Ministry of Forest and Soil conservation• Secretary, Ministry of Local Development• Two persons nominated by Government from known water resources andenergy specialist from non-Government sector• Dean Institute of Engineering, Tribhuvan University• President Nepal Engineers' Association• Representative, Federation of Nepalese Chamber of commerce and Industry• Secretary, Water and Energy Commission Secretariat- Member Secretary• WECS is now looking for a new partner to take on the emerging challenges
together in the area of water and energy sector planning and policy
formulation

Objectives of the WECS
• To provide assistance to the concerned ministries in formulating
policies and objectives to be included in the perspective/periodic
plan relating to the water resources and energy sector.
• To provide suggestions, recommendations and guidance withregard to the multipurpose (mega and medium scale only)
projects’ development as well as to irrigation, hydropower,
drinking water, industrial use of water, flood management andwater navigation; and also regarding the promotion anddevelopment of such mega and medium scale projects, andprotection of environmental aspects relating to the abovesectors.
• To formulate policies and strategies with regard to the water
resources and energy sector.
• To render opinion, advice and recommendations on bilateral andmultilateral issues relating to water resources and energy.

The Mandate of WECS
• To formulate necessary policies and strategies for conducting
study, research, survey andanalysis on various aspects ofwater resources and energy development in keeping with thepriorities and targets of GON.
• To enact the necessary laws pertaining to the development ofwater resources and energy.
• To establish coordination among national and sectoral policies
relating to water resources and energy sector.
• Identify the viable power projects and make an analysis ofbilateral and multilateral projects relating to the developmentof water resources and energy.

Location of Nepal

Hydro-physiology of Nepal in Brief• There are more than 6000 rivers and lakes within theterritory of Nepal• Total drainage area: 194,471 km2• Three Class of Rivers: Snow fed, Rain fed and Seasonal• Annual surface flow
225 billion m3• High altitude variation from 60 m in Terai (Jhapa) to7,500 m in high Himalayas within a span of 200 m inaverage.
• High Temporal variation (time) of annual rainfall, i.e.,
20% of total annual rainfall from October to May (8months) and 80% from June to September (4 months).
9

Physiography
Trans Himalaya

Legen

C H I NA
Kanjuroba
Annapurna
Langtang

Mt EverestHighHimalaya

Kathmandu
SimaraMidlands
Mahabharat Range
Terai Siwalik Range
10

Annual Mean Temperature °C30292827-80

18-1281-6082

6915832184

2785

86878811

Map of Glaciers and Glacier Lakes Distribution

ICIMOD/UNEP (2000)

Water Sector Scenario• Nepal has 225 billion cubic meters of water available
annually.
• About 15 billion cubic meters has been used for
economic and social activities.
• About 10% of total precipitation falls as snow( UNEP,2001)• About 23% of total areas of Nepal lie above
permanent snowline of 5000m( MOPE, 2004)• About 3.6% of total areas are covered by glaciers.

Water Sector Scenario contd..
• 30% of the global glaciers• 3,252 glaciers covering an area of 5,323 sq. km• 2,323 identified glacial lakes covering an areaof 75.7 sq. km

Water Balance of Major River BasinClimate Change• The United Nations Framework Convention on
Climate Change (UNFCCC), in its Article 1, defines“climate change” as: “a change of climate which
is attributed directly or indirectly to humanactivity that alters the composition of the global
atmosphere and which is in addition to natural
climate variability observed over comparable
time periods” .

Temperature Trend in Nepal• IPCC AR4 projects the global temperature torise by 1.1 to 6.4 degrees celsius, in anaverage 1.8 to 4 degree celsius• Analysis of 32 years observed data (1975 –2006) in Nepal shows a temperature increaseof 1.8 degrees celsius

Temperature Trends
patial Distribution of max. Temperature Trends

Langtang (3920 m a.s.l.)

0.00

82

84

86

88

Longitude ( oE)

-0.09

-0.05

0.00

0.05

0.09 R e g io n al M e a n T e m p e ra t u r e T ren d s f o r t h e p e ri o d 1 9 7 7 - 9 4 ( ° C p e r y e a r)

Color Coding of tem perature trends( o C year -1 ) R e g i o n sS ea s o n a l

A n n u al

W i n ter

P re -m o n so o n

M onsoonP o s t -m o n so o n

D ec - Fe b

M ar -M ay

J u n -S ep

O c t -N o v

JanT ra n s -H im al ay a0 .1 20.01

0.110.10

0.09

H i m al a y a0 .0 90.05

0.06

0.080.06

M i d d le M o u n ta i n s0 .0 60.05

0.06

0.09

0.08

S i w a lik

0 .0 20.01

0.02

0.08

0.04

T er a i0 .0 1

0.00

0.01

0.07

0.04

Precipitation

All-Nepal
32 a) All-Nepal
10-1-2-31950
196032 b) Himalaya W
10-1-2-31960

32 f) Terai/Siwalik W
10-1-2-31960

1970
3219801990c) Himalaya E

10-1-2-31970

1980

1990

32 d) Middle Mountain W
10-1-2-3
1960

All-Nepal Smoothed1960
321970

1980

1990

1970

1980

1990

1970

1980

1990e) Middle Mountain E

10-1-2-31970

1980

1990

1960
32g) Terai/Siwalik E

10-1-2-3

1970

1980

Years

1990

1960

Years

Not trends, only oscillations

Hydrometeorological observations
across Nepal
このイメージは、現在表示できません。

Annual Mean Temperature for Nepal, 1961-96

Temperature (deg C)

21.00

y = 0.0697x + 17.92
R2 = 0.7483;
n = 119; 72 < h (m) < 4100

20.00

19.00

18.00

17.00
1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995

Year

Hydrometeorological observations
across Nepal
このイメージは、現在表示できません。

Annual MeanTemperature fromhigh elevation gauges in Nepal, 1976-96
18

y = 0.1076x + 14.664
R2 = 0.7849;
n = 15; 1800 < h (m) < 4100

Temperature (deg C)

17
17
16
16
15
15
14
1976

1978

1980

1982

1984

1986

Year

1988

1990

1992

1994

1996

Retreat of the Khumbu glacierRetreat of the Lirung glacier
2003

Lower, debris covered, partis detached from the upper
part and has become amass of dead ice, which isdegrading rapidly, withrapid surface lowering,terminus retreat andponding in front.

Past GLOF in Nepal
NoDateRiver Basin

Name of Lake

1450 years ago

Seti KholaMachhapuchhare

2

August 1935

Sun Koshi

Taraco, Tibet

3

Sept. 21, 1964

Arun

Gelaipco, Tibet

Sun Koshi

Zhangzangbo, Tibet

451964

Trishuli

Longda, Tibet

6

1968

Arun

Ayaco, Tibet

7

1969

Arun

Ayaco, Tibet

Source: WECS 1998; DHM; ICIMOD

Past GLOF in Nepal …… contd.
No.

Date

Basin

Lake

8

1970

Arun

Ayaco, Tibet

9

Sep. 3, 1977

Dudh Koshi

Nare Tibet

10

June 23, 1980

Tamur

11

July 11, 1981

Sun Koshi

Nagma Pokhari,
Nepal
Zhangzangbo

12

August 27, 1982

Arun

Jinco, Tibet

13

August 4, 1985

Dudh Koshi

Dig Tsho14July 12, 1991

Tama Koshi

Chubung15

Sep. 3, 1998

Dudh Koshi

Tam Pokhari

Source: WECS 1998; DHM; ICIMOD

Retreating Process of Nepalese GlaciersImja Lake

Tsho Rolpa Lake• Glaciers are the “Water Tower of Asia” and provide
hydrological resource to 1.3 Billion people.
- Himalayan glaciers represent the largest snow cover region on theEarth’s surface outside the poles and make the headwater to major rivers
Ganges- Particularly important for snow/glacier cover is the western Himalayanregion.

• Himalayas govern the climate of Asia andsignificantly influence the onset and strength of theSouth Asian Summer Monsoon.
- The Indian monsoon accounts for over 70% of the annual rainfall and isdirectly influenced by the pre-monsoon elevated heating over theHimalayas-Tibetan Plateau and the subsequent land-sea thermal gradient.

Impact of Climate Change on Water
Resource

Specific case of Gandaki RiverBasinHydrological features of Gandaki River Basin• Catchment Area : 30,090 km2• Mean Annual Runoff : 1570 m3/sec.
• Specific discharge :Maximum: 0.045 m3/sec./km2
Minimum : 0.029 m3/sec./km2
Kali Gandaki at Kotagaon : 11400 km2
Myagdi Khola at Mangalghat catchment area: 1112 km2
Modi khola at Nayapul catchment area : 601 km2
Andhi Khola at Andhimuhan catchment area : 476 km2

Location of River Basins for flow trend analyses

Monthly trend of flow observed at the Myagdi River at
Mangal Ghat
Flow of Myagdi River in February
Station Location : Mangal Ghat , St. No. 404.7

D is ch a rg e (cu m e cs )

20
18
16
14
12
108
64
2016
14
12108
642

Year

Year

2005

2000

1995

1990

1985

1980

1975

1970

2005

2000

1995

1990

1985

1980

197501970

D is c h a rg e (cu m e c s )Flow of Myagdi River in January
Station Location : Mangal Ghat , St. No. 404.7

Monthly trend of flow observed at the Myagdi River at
Mangal Ghat
Flow of Myagdi River in April
Station Location : Mangal Ghat , St. No. 404.7
60
D is ch a rg e (cu m e cs )1816
14121086
4
2050
4030
20
10Year

Year

2005

2000

1995

1990

1985

1980

1975

1970

2005

2000

1995

1990

1985

1980

1975

01970

D is ch a rg e (cu m e cs )Flow of Myagdi River in March
Station Location : Mangal Ghat , St. No. 404.7

Monthly trend of flow observed at the Myagdi River at
Mangal Ghat

140120100806040Year

2005

2000

1995

1990

1985

1980

1975

2001970

2005

2000

1995

1990

1985

1980

1975

D is ch a rg e (cu m e cs )

160

Year
F

Flow of Myagdi River in June
Station Location : Mangal Ghat , St. No. 404.7

50
45
40
35
30
25
20
15
10501970

D is ch a rg e (cu m e cs )Flow of Myagdi River in May
Station Location : Mangal Ghat , St. No. 404.7

Monthly trend of flow observed at the Myagdi River atMangal Ghat

Flow of Myagdi River in August
Station Location : Mangal Ghat , St. No. 404.7

Flow of Myagdi River in July
Station Location : Mangal Ghat , St. No. 404.7

YearYear

2005

2000

2005

2000

1995

1990

1985

1980

1975

01995

50

1990

100

1985

150

1980

200

1975

250

450
400
350
300
250
200
150
100
500
1970

Dis charge (cum ecs )

300

1970

D is charge (cum ecs )350

Monthly trend of flow observed at the Modi River at Nayapul

Flow of Modi River in May
Station Location : Nayapul , St. No. 406.5

Flow of Modi River in June
Station Location : Nayapul , St. No. 406.5
100
Dis c harge (c umec s )302520
1510580
60
4020Year

Year

2000

1998

1996

1994

1992

1990

1988

2000

1998

1996

1994

1992

01990

01988

Discharge (cumecs)

35

Monthly trend of flow observed at the Modi River at Nayapul

Flow of Modi River in July
Station Location : Nayapul , St. No. 406.5

Flow of Modi River in August
Station Location : Nayapul , St. No. 406.5
300
Dis c harge (c umec s )

250
200
150
100
50

250
200
150
100
50

Year

2000

1998

1996

1994

1992

1990

2000

1998

1996

1992

1990

1994
Year

1988

001988Dis c harge (c umec s )300

Monthly trend of flow observed at the Andhi Khola atAndhimuhan

Flow of Andhi Khola River in June
Station Location : Andhi Mohan , St. No. 415

Year4030
2010Year

1995

1990

1985

1980

1975

1970

1965

01960

1995

1990

1985

1980

1975

1970

1965

D is charge (cum ecs )765432101960

D is charge (cum ecs )Flow of Andhi Khola River in May
Station Location : Andhi Mohan , St. No. 415

Monthly trend of flow observed at the Andhi Khola atAndhimuhan

Flow of Andhi Khola River in August
Station Location : Andhi Mohan , St. No. 415

Flow of Andhi Khola River in July
Station Location : Andhi Mohan , St. No. 415

Discharge (cumecs)

80
70
60
50
40302010080
60
4020

Year

1995

1990

1985

1980

1975

1970

1965

1960

1995

1990

1985

Year

1980

1975

1970

1965

01960

Discharge (cumecs)

100

Monthly trend of flow observed at the Badi Ghat Khola atRudra Beni

Flow of Badi Gad Khola River in August
Station Location : Rudra Beni , St. No. 417

Year

2000

1995

1990

1985

1980

2000

1200
1000
800
600
400
20001975

Discharge (cumecs)

Year

1995

1990

1985

1980

700
600
500
400
300
200
10001975

D ischarge (cumecs)

Flow of Badi Gad Khola River in July
Station Location : Rudra Beni , St. No. 417

Impact of Climate Change• Days and nights are becoming more warmer• Cool days and nights are turning
lessPrecipitation trend is not as apparent as
temperature but increased trend is indicated• Number of rainy days with >= 100 mm areincreasing• Number of rainy days are decreasing• Extreme events are increasing

Impact on Glaciers• Glaciers in the Himalayas are retreating fast:
Rikha Samba glacier, AX010, Yala and Imja aresome of the observed.
• Glaciers are retreating very fast from several
meters to 50 meters per year.

Impact on water availability• Increase in Extreme events (temperature,precipitation) pose a great threat to the riverdischarge.
• Dept. of Hydrology and Meteorology study
showed an increase of 13% more flow on
Karnali River on a 4 degree temperature riseand 20% precipitation increase.

Impact on Water Sectors• Extreme weather conditions make thehydropower projects more vulnerable• The dry period will invite more uncertainties
on power generation capacity• Sediment load will also cause problems

Impacts on water sectors contd..
• Drinking water supply will be critical• Intense precipitation, Increased flood runoff and a great threat:floods of catastrophic nature, long inundation period, landdegradation,• land slides, mass wasting, heavy sediment load,Increased soilerosion.
• Increase in flood and droughtmagnitude and damages;

Conoclusions• Climatic change affects hydrology of river basin such as
timing of water availability and quantity as well as quality.
• Change in hydrology induce risk to water resources
facilities( flooding, landslide and sedimentation).
• The impact of climatic variability on water resources
depends not only on change in volume and quality but
also on system characteristics.
• Snowfed rivers have early shifting non_ snowfed rivers
have late shifting of hydrograph.
• Climate variability produce excess water in wet period
and less river discharge in dry period .
• The assessments of the climate change impacts are very
essentials for efficient and effective planning of water
resources in sustainable manner.

Thank you.