Water-related adaptation to climate change

Water for a food-secure world

Water-related adaptation to climate change

Alemseged Tamiru Haile (Ph.D.)28 January 2014

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

Water scarcity

Physical scarcity: Not enough water.

Economic Scarcity: Not infrastructure to make water available to people

Both scarcities should be managed


Distribution of the percentage of area under irrigation

Ample room for development

Irrigated Land (% of Crop Land)

0

5

10

15

20

25

30

35

40

45

South Asia Middle East &North Africa

East Asia &Pacif ic

Latin America &Caribbean

Sub-SaharanAfrica


Climate change: change in the statistical properties of the climate system

Economy, Population, Technology

Increased GHGE

Anthropogenic Global warming

Regional Changes

Precipitation, Temperature, sea level

Impact

Water, Agriculture, Energy, etc.

Measures

Mitigation, Coping, Adaptation

Loss and damage

Average condition, Variability, Extremes

Demand, Supply, Reservoir evaporation, Infrastructure damage

Fossil fuel, GW pumping, Land use change, Livestock

Adapt to (i) less soil moisture and higher evaporation, (ii) Increased floods


Climate change adds new challenges


Source: Maartin de Wit and Jacek Stankiewicz www.scienceexpress.org/2March2006/Page1/10.1126/science1119929

African Scenarios – uncertainty is the keyword!

Small changes in temperature will see average river flows and water availability increase by 10-40% in some regions, while in others there will be a decrease of 10-30%

Changes in surface water supply across Africa with Predicted Climate ChangeIncreases and decreases:

Potential ET

Actual ETRunoff

10 models show likely decrease of runoff 7 shows like increase of runoff

Example: Blue Nile GCM Downscaling

Precipitation


Climate change: Ethiopia

• Studies show impact of CC on Sectors• By 2050 climate change could cause [Robinson et al., 2013]:

– GDP to be 8–10 percent smaller than under a no-climate change baseline;

– a two-fold increase in variability of growth in agriculture; – it would affect more severely the poor and certain parts of

the country.

• ADAPTATION IS THE PRIORITY


Barriers to adaptation (Based on Deressa et al., 2009 and Haile et al., 2014)

• Farmers’ perception is there is long-term temperature and precipitation change

• The least practiced adaptation strategy by HHs in the Nile basin is - Irrigation

• Barriers to adaptation– Not knowing which kind of

measures to take– Insufficient financial means – Shortage of labor



Despite its high productivity, irrigation is under growing pressure to reduce its environmental impact, including soil salinization and nitrate contamination of aquifers



• Inadequate storage leaves farmers vulnerable to CC• Store water for use in times of shortage• Continuum of storage: Reservoirs, Ponds and tanks, aquifer,

soil moisture• The best option is to focus on

– Combining a variety of storage types– Consider CC in planning, design and operation– Types of storage – tailored to specific conditions


Household Irrigation Technology (HIT) to transform Ethiopian agriculture sector

• Agricultural intensification - “Save and Grow” - requires– Target households– Knowledge-based precision irrigation– Use of improved, drought tolerant varieties and management practices

that save water – Reliable and flexible water application

• Deficit irrigation

• Estimates over the next 5 years indicate HIT could enable:– Over 500,000 ha could be irrigated - Doubling existing irrigation– >650,000 farming households to become agricultural entrepreneurs, – increasing family income and food security for almost 5 million

Ethiopians – Adding $600 million USD and 30,000 jobs to the national economy


7 major bottlenecks in the Household Irrigation sector of Ethiopia (Source: ATA)

1. Lack of readily available information on groundwater resource potential– to recommend technically feasible water lifting and saving

technologies2. Lack of data on high value crops for specific agroecology of the woredas3. Absence of well-trained manufacturers to produce quality manual and

mechanized HITs for smallholders, and lack of clear standards for HITs4. Lack of reliable and interdependent HITs and other irrigation agriculture

input supply chain5. Absence of credit access to smallholder farmers to purchase HITs and

other agriculture inputs during irrigation season6. Smallholders are not getting the right training and advisory support on

irrigated agriculture and the agriculture research system offers limited attention to high value crops

7. Frequent HIT failures and absence of locally available maintenance services or spare parts


Adaptive management of groundwater (AMGRAF)

• Aim: to enable sustainable development of accessible (shallow) groundwater for small-scale irrigation

• Assessment of groundwater resource and use• Development of tools for adaptive groundwater management• Research into scenarios of water management• Socio-economic: Livelihood impact, governance, institutions

• Working definition of ‘accessibility’– The depth to GW should be less than 30m


Adaptive management of groundwater (AMGRAF)

Key findings include (eg):• There is some experience of GW use• GW resource is not evenly distributed among households• How to break Hard rocks to access water below 10-15 metres?• Overexploitation???• Limitations to expanding use of irrigation include: water lifting

mechanisms; wells dry out, scarcity of land; shortage of seedlings• If more irrigation available, would grow vegetable crops (onions, cabbage,

pepper, garlic etc)


Spate irrigation

“Floods are not always a hazard. They may also sustain aquatic life and riverine biodiversity, recharge aquifers, enrich soils and in some of the world’s poorest areas they are the main source of irrigation.”

Global Water Partnership (2000) ‘Toward water security: a framework for action’

• Expansion of Spate Irrigation due to – Physical reasons

• Lowlands: extensive flat, fertile surrounded by hills with high rainfall• The expansion of agriculture to the mountains

– land degradation, reduced base flow, increased drought– Socio-economic reasons

• Increased population in the lowland areas - increased demand• provides the livelihoods for economically marginal people

Water for a food-secure world

Spate irrigation

• Climatic factor for use of SI:– Reduced rainfall – Increased dry spells – Increased temperature

• Challenges:– Unpredictable floods– Frequent damage of structures

• Increased floods– Encourage SI

Farmers observations over the last decade

Observation % of farmers

Rainfall decreased 63

LGP reduced 85

Temperature increased 73

Freq. of dry spells increased

64

Volume, freq. and duration of spate flow decreased

90

How to properly to divert and manage the flood water for crop production?


IMPACT2C• Several reservoirs planned in Blue Nile

– Target ensuring food security at households-E.g. Upper Beles:~20000 HHs• What is the link between these reservoirs?

– Upstream-downstream trade-offs and opportunities– Hydropower, irrigation, environment– Water allocation

• CC impact on – Demand and supply

• Role of reservoirs - adaptation– Variability vs supply– Flood control– Water allocation


IMPACT2C

• Quantifying projected impacts under 2°C warming• Global climate modeling (GCM), dynamic regional

downscaling (RCM), and bias correction • Set of models and approaches can be used to assess impact

• SWAT, HBV • WEAP,• CROPWAT,

Mendlik and Gobiet (2013)


Conclusion

• Better communicate CC uncertainty • Adapt to less soil moisture and increased floods• Invest in R&D to enhance adaptation • Accessibility is more important than potential – infrastructure

– RWH (in-situ soil moisture maximization, ponds) – Shallow GW wells

• Provide more and diverse physical storage infrastructure• Consider CC in planning, design & operation of storage schemes• “Save and Grow”

– Irrigation technologies (treadle pumps, hand pumps, drip irrigation) and water saving


THANK YOU!!!

Water-related adaptation to climate change

Documents

foodsecure worlddistribution

foodsecure worldbarriers

foodsecure world source

ccstore water

managed water

development water

water available

priority water