Download - Soil water, irrigation and climate change
WG2: SOIL WATER, IRRIGATION AND CLIMATE CHANGE
Eulampius Frederick Saint Lucia
Vardhui Surmalyan Armenia
Eranga Sampath Sri Lanka
Samuel Karongo Kenya
Group Members
Cristina Sosa Sosa Ecuador
IntroductionClimate Change is defined as statistically significant variation in either mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). Climate change may be due to natural internal processes or external forcing or to persistent anthropogenic changes in the composition of the atmosphere or in land use (IPCC, 2001).
Introduction
The average predicted temperature increase over the next 100 years is around 3 degrees centigrade. This compares to an increase of about 1 degree centigrade due to previous man-made greenhouse gas emissions (Source: IPCC)
If the predicted increases in greenhouse gas concentrations are then translated into temperature changes, a global temperature increase of between 1 and 5.5 degrees centigrade is predicted for 2100 (Source: IPCC)
Introduction
change in rainfall patterns
rise in temperatures and sea level potential
droughts
habitat lossheat stress
floods
Effects of Climate Change include
Introduction
Rising temperatures and changing rainfall patterns may increase or decrease agriculture’s water demand.
Irrigation
Irrigation water requirements strongly depend on factors such as biophysical conditions, crop type and water use efficiencies.
We will face a general trend of increasing area of land under irrigation but decreasing water use intensity
Meeting rising food demand necessitates increased crop land
Water efficient irrigation methods
Population increase
Sprinkler systems (efficiency 70-80%)
Drip systems (efficiency 90-95% )
Furrow irrigation (efficiency 30- 50 %)
Irrigation
Predictions
UNDP study - national scenarios forecast over next century
Increase of climate aridity and intensification of desertification processes
Plant cultivation reduction efficiency 8-14%
Decrease in precipitation of about 9 % and annual river flow 15 %
Armenia
• Average temperatures are likely to rise in the range of 0 to 4.5 degrees centigrade by 2090
• Rainfall seasonality and amounts is expected to remain the same but intensity is projected to increase by 2100.
• Increased number of wet seasons leading to severe flooding.
• Frequent and severe droughts
Kenya
• An overall warming of between 1 and 5 degrees Celsius or greater is expected
• Increased number of hot/dry days and nights, dry spells will become more pronounced
• Fewer but more intense rainfall events.• Amount of precipitation received annually is,
however, not expected to change significantly• Increased flooding as well as hillside erosion and
sediment transport.• Increasing temperature is expected to increase
evapotranspiration rates thereby reducing soil moisture
Saint Lucia
• By 2100, temperature during the southwest monsoon season (May - Sept) is anticipated to be 2.5 ºC, whilst the northeast monsoon season (Dec - Feb) is expected to yield a temperature increase of 2.9 ºC
• Tropical cyclone intensity is expected to rise by 10 - 20%
• Rise in sea level A 30-50 cm sea-level rise (projected by 2050) will threaten low islands and coastal zones
Sri Lanka
• The temperature is predicted to increase from 1 - 4 °C (IPCC).
• The precipitation will not change much in the year, but the rainfall patterns will change
• Melting of the glaciers
Ecuador
Problems
• Droughts• Floods in the Coast region (wet season)• Distribution of the water for agriculture, industry,
domestic use, hydropower plants• Loss of crops lands• Decreasing of the flows in the rivers: our energy
depends directly from the hydropower plants, that is why this last time we have faced energy problems.
Ecuador
• Sea water intrusion to agricultural lands• Reduce the quality of irrigation water in coastal
regions.• High temperature regime will also increase the
evapotranspiration losses leading to frequent soil moisture stress conditions.
• High intensive rains (>25 mm/hr). Such rains will wash off the fertile top soil of arable lands.
• Salinization of agricultural lands in semi-arid parts of the country.
• Increased cloud cover and rainfall could decrease yields of many crops (rice, sugar cane etc).
Sri Lanka
• In clay type soils, increasing temperatures coupled with prolonged dry spells will lead to desiccation cracking that will further enhance soil moisture loss. Soil becomes unmanageable.
• It is anticipated that surface water systems will experience increasingly variable stream flows and reduced water levels.
• Decreased water available for irrigation.• Loss of fertile topsoil due to erosion and sediment
transport during floods.• Salinisation of topsoil from fertilizer use
Saint Lucia
• High evapotranspiration rates, need for more irrigation water.
• Extreme droughts will lead to soil moisture being drastically reduced.
• Flooding will cause loss of fertile top soil and damage to irrigation infrastructure
• Loss of crop lands from sediment deposition• Increased conflicts over water resources
Kenya
Reduced soil moisture Reduced availability of water for agriculture
Loss of arable land
Armenia
Adaptation StrategiesHow to overcome these problems?
Examples and the solutions done in each country
Planning efficient use of water resources
Improving water infrastructure for
irrigation
Integrating climate adaptation for
agricultural sector development
Armenia
• Information sharing on impacts of climate change• Water harvesting and conservation• Flood protection measures e.g. levees, dikes.• Use of water efficient irrigation systems
Kenya
• Drip irrigation• Greywater re-use• Desalination of sea water?• Use groundwater (this may lead to saltwater
intrusion)• Growing of cover crops• Mulching
Saint Lucia
• crop recommendation based on the agro-ecological suitability;
• promote on-farm soil and moisture conservation;• rain water harvesting (domestic and on-farm)• rehabilitation of irrigation canal network and
minor tanks to operate at their design capacity ;• re-use of drainage water• program to improve the water use and
conveyance efficiency;
Sri Lanka
• breeding for short age varieties;• strengthen the breeding program for; a) drought resistance b) high temperature resistance c) pest and disease resistance d) salt resistance• effective use of long range weather forecasting for agricultural planning
Sri Lanka
• Building water infrastructure for irrigation• Efficient irrigation methods e.g. drip, sprinklers• Modeling possible effects in regional and local
environments. • Implement flood mitigation measures e.g. dikes, dams and
artificial reservoirs.• Integrate conservation and crop plague management.• Treatment of river water to make it suitable for irrigation.• Afforestation using adaptive tree species• Strengthen the breeding for drought resistance crops.
Ecuador
Challenges in Implementing Adaptation Strategies
• Financial constraints• Insufficient baseline data and research.• Limited awareness of climate change impacts
and adaptation strategies.• Insufficient stakeholder co-operation• Inadequate or non-supportive legislative and
institutional frameworks.
Conclusions
text
Water scarcity remains one of the main problems arising from climate change.
Rainfall patterns are expected to change
The economic development of emerging countries will depend on how they empower their small farmers to adapt to climate change, i.e. training them on the use of efficient irrigation systems
Need for more research and financial and technical support to cope with climate change
Danke