Climate Change Adaptation Strategies to Cope with Water-related Disasters due to Global Warming
Water-related adaptation to climate change
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Transcript of 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
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Water scarcity
Physical scarcity: Not enough water.
Economic Scarcity: Not infrastructure to make water available to people
Both scarcities should be managed
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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
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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
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Climate change adds new challenges
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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
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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
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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
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Water-related adaptation to climate change
Despite its high productivity, irrigation is under growing pressure to reduce its environmental impact, including soil salinization and nitrate contamination of aquifers
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Water-related adaptation to climate change
• 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
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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
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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
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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
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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)
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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
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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?
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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
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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)
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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
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THANK YOU!!!