Irrigation Water Requirements in Regions along Euphrates River in Iraq: Role and implications of Climate Change

Abstract

This research aimed to predict how projected climate change will affect the quantity of water needed for irrigation. The case study focused on the Iraqi cities of Anbar and Babylon, located in the Euphrates River Basin (ERB). The CROPWAT model was fed by current and future climate data. Three climate change scenarios for the reference period from 1995-2014, SSP1-2.6 (2020-2039) and SSP2- 4.5 (2040-2059), were implemented in this research. The obtained results showed that annual increases in the temperature for Anbar are 1.1 and 1.85 °C, and for Babylon, they are 0.9 and 1.88 °C for the two scenarios SSP1- 2.6 and SSP2-4.5 concerning the reference period scenario. In addition, the annual decrease in precipitation is 3.61 and 4.63 mm for Anbar and 3.61 and 2.66 mm for Babylon Province. The average annual reference evapotranspiration for the three climate scenarios is 157, 202, and 206 mm for Anbar and 187.5, 195.6, and 224 mm for Babylon Province. The total annual irrigation water requirements for the crop growth cycle are 1.10, 1.43, and 1.46 for Anbar and 3.96, 4.13, and 4.76 billion cubic meters for Babylon.