Assessment of water quality along Greater Zab River within Iraqi lands

Abstract

The current study examined the assessment of the waters of the Greater Zab River GZR because it represents the most important and largest tributary of the Tigris River due to its participation in about 40% of the Tigris River water and because it is a large basin and catchment area. The GZR consists of the gathering of streams, starting from the areas near Lake Van, and then entering Iraqi lands in the Kurdistan region towards the Tigris River. It passes through several geological formations, most of which are containing carbonate rocks composed of calcite and dolomite, which have solubility due to the effect of rainwater. Therefore, several streams gather and empty into the main valley GZR carrying the weathering products of these rocks as soluble ions. It was found through chemical analyzes of the main cations (Ca2+, Mg2+, Na+, K+) and anions (HCO3-, SO4=, Cl-, NO3-), as well as measuring the pH, electrical conductivity (E.c.), total dissolved salts (TDS), total hardness (TH) and turbidity (Tr.), The GZR waterfalls within the natural limits set by the World Health Organization for drinking purposes through the use of the water quality index (WQI) as well as its suitability for agricultural purposes according to the standards of Sodium Percentage (SSP), Sodium Adsorption Ratio, (SAR), and the amount of Residual Sodium Carbonate (RSC). As well as, the percentage of magnesium (MAR).