Preliminary Assessment of Hydrothermal Risks in the Euphrates–Tigris Basin: Droughts in Iraq

This paper presents a temporal and spatial pattern of precipitation, surface air temperature, and drought occurrence in Euphrates–Tigris rivers basin with special emphases on Iraq. Historical records based on 115 years (1900–2014) of monthly precipitation and temperature data has been divided into four sub-periods, each of 30 years (first 1900–1929, second 1930–1959, third 1960–1989 and fourth 1985–2014) and studied separately. The results showed that the mean annual precipitation in Iraq for the four sub-periods is: 218.5, 202.1, 196.4, and 174.9 mm respectively, with an average of 198 mm. This indicates that the mean annual precipitation decreased by 43.6 mm (20 %) in the fourth sub-period compared to the first sub-period. The mean annual temperature for the four sub-periods in Iraq are 22.0, 21.9, 22.0, 22.8 °C respectively, with an average of 22.2 °C. This indicates that the average monthly temperature during the year in Iraq increased by 0.76 °C (3.45 %) in the fourth sub-period compared to the first sub-period. The probability of occurrence of dry (hot) periods in Iraq increased by 345.5 % (147.7 %) in the fourth sub-period compared to the first sub-period. Fortunately, the greatest drought occurrence is observed in western parts of Ira, where agriculture is irrigated, in rain-fed areas in the northern Iraq, there has also been a decrease in precipitation, but not so strong as in the west of the country. A preliminary conclusion about the current climatic desertification and its possible consequences for Iraq was drawn.