Future of water and agriculture in Sri Lanka in the face of climate change, Nishadi & Vladimir Smakhtin

Water for a food-secure world

FUTURE OF WATER AND AGRICULTURE IN SRI LANKA IN THE FACE OF CLIMATE CHANGE

Nishadi Eriyagama & Vladimir Smakhtin (IWMI)

GWP Workshop on Climate Change Food and Water Security

Colombo, Sri Lanka, February 2011

Water for a food-secure world Water for a food-secure world

• Climate change signals in Sri Lanka – observed changes

• What will the future hold? – projected changes

• Impacts

– On water resources

– On agriculture

• Climate change vulnerability hotspots?

• Responding to climatic changes

• Knowledge gaps

OUTLINE

Food Security


INFORMATION SOURCES

Sources

IWMI climate change vulnerability mapping

Over 75 national and global climate change studies

Interviews and e-mail correspondence with

-Government officials -International experts

16

Preliminary review of recent floods


Dry Zone

Wet Zone

Intermediate Zone

Warming trends (0C/year) 1961-2000

OBSERVED CHANGES

Temperature

Source: Zubair et al. 2005

Anuradhapura 0.024-0.026

Badulla 0.022-0.024

Rainfall

No significant change in Mean Annual Rainfall Amount

South-West Monsoon (May – Sept): Stable (Yala)

North-East Monsoon (Dec – Feb): reduced & variability increased (Maha)


PROJECTED CHANGES - 1

• General consensus: increasingly warmer in 21st century

• IPCC: stronger warming than the global mean in South Asia

• Projected magnitude of change: differs from study to study

Temperature

Source Model Scenario Base Year Change at end

21st century

Cruz et al.

2007

AOGCM A1F1, B1 1961-1990 + 2.93-5.44 0C

Kumar et al.

2006; Islam

and Rehman

2004

Regional

Climate

Model-RCM

A2, B2 1961-1990 + 2-4 0C

Basnayake et

al. 2004; De

Silva 2006

Statistical

Downscaling

of GCMs

A1F1, B1,

A2, B2

1961-1990 + 0.9-3 0C


Lower Mean Annual Rainfall

Mean Annual Rainfall

Higher Mean Annual Rainfall


Rainfall

Increased Variability Increased Floods & Droughts

- Projections for this century confusing and contradictory!

Higher South-West Monsoon R/F

Higher North-East Monsoon R/F

Higher South-West Monson R/F

Lower North-East Monson R/F

Kumar et al 2006; Islam and Rehman 2004; Basnayake et al. 2004; Basnayake and Vithanage 2004 a

Cruz et al. 2007; De Silva 2006; Basnayake and Vithanage 2004b

Lower South-West Monsoon R/F

Lower North-East Monsoon R/F

Ashfaq et al. 2009; Basnayake et al. 2004


Dry Zone

Wet Zone

Intermediate Zone

Dry Zone

Wet Zone

Intermediate Zone


Spatial Pattern of Rainfall Projections for 2050s

Projection 1 Projection 2

De Silva, 2006

De Silva 2006 Basnayake et al. 2004

+

+

+

+

+

+

+

+

+

+

+

- -

- - - -

- -

-

+

+

+ +

+

+ +

+

+

+

Dry Zone

Wet Zone

Intermediate Zone

Projection 3

De Silva, 2006

Punyawardane et al. 2010

- -

- - - -

- -

- +

+ +

+

+

+

Ambiguity!


IMPACTS ON WATER RESOURCES

• Dominant School of Thought: Gain in Mean Annual Water Availability

• But increased temporal and spatial variability

• Brunt of impact on north eastern and eastern dry zone: May become even drier!

• Increase in Soil Moisture Defecit in the Dry and Intermediate zones by 2050 (De Silva 2006): More irrigation?

• Lower water availability in the upper Mahaweli watershed by 2025 (Shantha & Jayasundera 2005): More power cuts?

Dry Zone

Wet Zone

Intermediate Zone

No comprehensive national study!


Sea Level Rise: Inundation + Salt intrusion

40% of National GDP from coastal zone

IMPACTS ON AGRICULTURE

Paddy Tea Coconut

Yield:

• 0.1-0.5 0C temp increase:

1.2 to 5.9% reduction

(Vidanage &

Abeygunawardena 1994)

• Temp increase + CO2

increase: 24-39% increase

(De Costa et al. 2006)

Yield:

• 100 mm monthly R/F

reduction: 30-80 kg

reduction in ‘made’ tea/ha

• Increase in ambient CO2

concentration to 600 ppm:

33-37% increase

(Wijeratne et al. 2007)

Yield:

• Production after 2040:

not sufficient for local

consumption

•Increased pest and

disease problems -

reduce yield (Peiris et al.

2004)

Irrigation Requirement:

13-23% increase in Maha by

2050 (De Silva 2006)

Spatial Impact:

• Cultivations at low and

mid elevations more

vulnerable (Wijeratne et

al. 2007)

Economy:

Losses in the range $32 -

$73 million (Fernando et.

al 2007)

Economy: Rs. -11 billion to Rs. +39 billion by 2100 (Seo et. Al. 2005)


CLIMATE CHANGE VULNERABILITY HOTSPOTS-1

Climate Change Vulnerability Index

Anuradhapura

Nuwara-Eliya

Ratnapura Sensitivity Index

Exposure Index

Adaptive Capacity Index


CLIMATE CHANGE VULNERABILITY HOTSPOTS -2

Exposure Index based on: Frequency of exposure to historical droughts, floods, cyclones

Sensitivity Index based on: Population density, % employed in agriculture, irrigation water availability, agricultural diversity (crops diversity, livestock farming, fishing)

Adaptive Capacity Index based on: education level, poverty incidence, level of infrastructure development

0 – lowest vulnerability 100 – highest vulnerability


CLIMATE CHANGE VULNERABILITY HOTSPOTS -3

Anuradhapura

Nuwara-Eliya

Ratnapura

Highly vulnerable areas are:

• Typical farming areas

• Have low socioeconomic and infrastructural assets (low adaptive capacity)

• Show high levels of exposure to historical climate extremes

• Primary food producing areas - rely heavily on

water availability for agriculture


Response

Mitigation Adaptation

Research

Knowledge

RESPONDING TO CLIMATIC CHANGES - 1

•Signatory to UNFCC and Kyoto Protocol

•Second National Communication prepared

•Small hydropower CDM projects

•Others – “Green Lanka” program

•National Adaptation Strategy

•“No Regrets” interventions

Eg: Restoration of the ancient tank system


Adaptation

RESPONDING TO CLIMATIC CHANGES - 2

Crops

•Development of heat/salt/pest resistant short term crop varieties by 6 research institutes. eg. Rice Research and Development Institute (RRDI)

•Crop diversification, change of planting time and location

Climate Tools

•Predicting annual national coconut production

•Predicting seasonal water availability within the Mahaweli scheme

Water Resources

•Restoring existing tanks

•Developing sustainable groundwater

•Rainwater harvesting and storage

•Use of micro-irrigation

•Wastewater reuse

•Greater shift towards alternative energy from hydropower

Sea Level Rise

•Climate Change Adaptation Action Plan by Coast Conservation Department (CCD)


• Detailed and quality controlled climate scenarios

• Flood and drought forecasting systems

• National Water Resources Audit eg. Prototype web tool by IWMI

• Comprehensive national study on vulnerability of water resources and agriculture to climate change covering:

– Both surface and ground water

– Water quantity and quality

– Combined impact of enhanced CO2 + temperature + increased/decreased rainfall on agriculture

• Central agency to cater to the need for corporation and data sharing

KNOWLEDGE GAPS

http://idistest.iwmi.org:8080/slwa/

http://idistest.iwmi.org:8080/slwa/


THANK YOU !

ACKNOWLEDGEMENTS: • Mr. Lalith Chandrapala, National Disaster Mitigation Council (NDMC) • Dr. B. V. R. Punyawardane, Department of Agriculture • Ms. Dharshanie De Silva, World Bank • Ms. Chandanie Panditharatne, Ministry of Environment and Natural Resources • Mr. Sarath Premalal, Department of Meteorology • Mr. Bandula Wickramarachchi, Coast Conservation Department (CCD) • Mr. N. Wickramaratne, Mahaweli Authority • Mr. H. M. Jayatillake, Irrigation Department • Mr. K. A. U. S., Imbulana, Ministry of Irrigation • Mr. L. Manawadu, University of Colombo • Dr. W. M. W. Weerakoon, Rice Research and Development Institute (RRDI) • Ms. Karin Fernando, Centre for Poverty Analysis (CEPA) • Dr. G. G. A. Godaliyadda, Irrigation Department • Dr. A. W. Jayawardena, Public Works Research Institute, Japan • Mr. Gerard Fernando, National Water Supply and Drainage Board • Mr. Harsha Sooriyarachchi, Water Resources Board • Staff of Sri Lanka Association for the advancement of Science (SLASS) • Dr. Herath Manthrithilake (IWMI)


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Number Affected Damage (000 US$)

Source: "EM-DAT: The OFDA/CRED International Disaster Database

Top ten Natural Disasters from 1901 to 2000Number Affected

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Future of water and agriculture in Sri Lanka in the face of climate change, Nishadi & Vladimir Smakhtin