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