Water quality determination in Khuzestan creeks, northwest of Persian Gulf using WQS Index

Abstract

Water quality was studied in Mahshahr creeks from 2005-2006. Due to special characteristics of Mahshahr creeks, high fisheries potential and sever exploitation and human pressure, WQS index was selected for determination of ecological health status of the area. Eight creeks Ghannam, Zasngy, Doragh,Ahmady, Darvish, Patil, Ghazaleh and Bihad were selected and monthly sampling of physical and chemical parameters was done by bottle sampler. Six primary water quality parameters were used to develop an integrated measure of overall water quality. The parameters included Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD sub(5)), Total nitrogen (TN), Total phosphorus (TP), pH and Ammonia (NH3). The results of two ways ANOVA showed that differences were significant only for nitrite between seasons and for pH, ammonium, nitrite and total phosphorus between creeks. Based on index description, parameters pH, NH3 and DO were placed in grade five indicating good quality for water. Total nitrogen was in grade three indicating poor quality and BOD5 and total phosphor were in grade one showing bad quality for water. According to the index, high similarity was found in studied creeks and the total value was found to be 3.33 for the whole studied area, indicating poor water quality.