ESTIMATE OF IRRIGATION REQUIREMENTS UNDER CLIMATE CHANGE SCENARIOS (A1 AND B1) FOR OLIVE TREES IN EGYPT

Abstract

The impacts of climate changes on irrigation requirements of olive trees under different climatic zones were studied using actual previous data of 2000 to 2007 for all studied regions. These data were used to generate the climatic data under climate change conditions by using magicc\scengen. The major governorates cultivating olive trees located in five agricultural climatic regions were selected; Ismailia Governorate in the Nile Delta, Fayoum Governorate in middle Egypt and Assuit Governorate represented the in Upper Egypt. Matruh and North Sinai have large cultivation area in outside the Nile valley. Furthermore, the irrigation requirements for olive trees in all the studied regions were calculated. The target of this step was comparing the irrigation requirements of different climatic regions under current and future climate conditions. The FAO equation was used to calculating the irrigation requirements for olive trees under current and future conditions. The future climatic values (2050 and 2100) were entered to the model individually. Two climate change scenarios (A1 and B1) were used to assess the consequences of climate change on irrigation requirements for olive in two time slices (2050, and 2100). The results indicated that the highest evapotranspiration and irrigation requirement for olive trees were obtained in Assuit 11.36 mm/day in July and irrigation requirement (4174 m 3 /feddan/year), respectively, followed by Fayoum 10.85 mm/day in July, (3997 m 3 /feddan/year) under A1 scenario. While, the lowest ETo value was obtained in Fayoum 2.02 mm/day in January and the irrigation requirement was found to be (2942 m 3 /feddan/ year) in Ismailia. Furthermore, A1 scenario has higher ETo and irrigation need value than B1 scenario. The ETo and irrigation requirements under 2050s were lower than those under 2100s under both tested scenarios. The highest water use efficiency (WUE) was obtained by Fayoum Governorate followed by Assuit Governorate under current climate conditions. Under climate change scenarios the highest WUE was obtained under Fayoum condition and the lowest WUE under North Sinai.