Water Quality Index for Assessment of Water Quality of Duhok Lake, Kurdistan Region of Iraq

Water quality of Duhok Lake was evaluated by Water Quality Index (WQI) technique. A water quality index provides a single number that expresses the overall water quality at a certain location and time based on several water quality parameters. The objective of an index is to turn complex water quality data into information that is understandable and usable by the public. Ten most important parameters such as pH, electrical conductivity (EC), total hardness, total alkalinity, dissolved oxygen (DO), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and sulfate (SO4) were taken for the calculation of WQI. The result indicated that water quality of Duhok Lake poor in the years 1999, 2000 and is poor in 2009 too. The impact of various anthropogenic activities was evident on some parameters such as the EC, alkalinity and hardness. It is suggested that monitoring of the lake is necessary for proper management. Application of the WQI is also suggested as a very helpful tool that enables the public and decision-makers to evaluate water quality of lakes in Iraq.