Global Climate Change and Its Effects on Irrigation in Mediterranean Region - Water and Energy Saving Irrigation Systems and Some Relevant Research Results

The average global temperature has increased by about 0.5 degrees C over the past 100 years in a continuing trend towards a warmer planet. This warming is closely associated with rising levels of CO2 in the atmosphere, which have increased by about 30% over the past 200 years. The most recent studies showed that the climate in Turkey also has been affected. As a result of global climate change, precipitation may decrease in some regions and water stored in lakes and reservoirs may suffer increased losses due to evaporation, reducing the water available for irrigation, municipal supplies, and for all other uses. So, urgent need for the most efficient use of existing water resources has enforced nations to give top priority to water saving technologies. Recently, drip irrigation systems are becoming more common among the pressurized irrigation methods and have been widespread all around the world due to low-cost drip pipes. Quite a lot of research on the drip irrigation method has been carried out in Turkey for the last two decades. Research results showed that the quantity of irrigation water applied in pressurized irrigation systems (drip, sprinkler, mobile sprinkler and LEPA-Low Energy Precise Application) were 30 to 50% less than surface irrigation methods for about the same optimum yields. Drip irrigation method was the most effective method as compared with the other methods. Many countries, such as Turkey, India and China revised their irrigation legislation, subsidizing their farmers for water and energy saving irrigation equipment. At present, the global coverage of sprinkler and micro irrigated areas are 33 million hectares (Mha) and 6 Mha, respectively all over the world.