Using the Irrigation Water Quality Index to Assess the Suitability of the Tigris River Water for Irrigation Purposes Between Al-Shirqat and Tikrit Sections in Salah al-Din Governorate

The Tigris River water is subject to significant changes in its physical, chemical, and biological properties, most notably due to several factors, most notably the construction of dams in Turkey and successive climate changes. Therefore, the current study aims to monitor and evaluate temporal and spatial changes in water quality in four sections (Sharqat, Zab, Baiji, and Tikrit) located on the Tigris River in Salah al-Din Governorate for irrigation purposes, using the Irrigation Water Quality Index (IWQI) technique. The study period extended from January to July 2024. During this period, five variables were selected and studied: electrical conductivity (EC), sodium adsorption ratio, chloride, sodium, and bicarbonate, due to their direct impact on the suitability of river water as a source of irrigation water. The study showed that both the north and south of the study area had high values ​​for electrical conductivity (EC), chloride (Cl-), and sodium (Na+) concentrations. The results also revealed that all sectors fall into the second category (76.02-80) when using IWQI, therefore, using river water for irrigation could increase the soil salinity problem if a drainage system is not provided in Salah al-Din Governorate.