statistical analysis of dez river water quality, southwest of iran

Dez river is considered as one of the highest water rivers after karoon river, supplying water for tens of towns and villages as well as thousands of acres of agricultural lands, several fish farming plans and industrial factories. hence, the water quality of dez river is one of the major concerns of the area. this study was carried out using descriptivestatistical method based on a 39 year time span statistics. a number of 394 samples were analyzed and the concentration of physical and chemical parameters including ph, tds, sar, total cations and anions were measured. the obtained results were examined and compared based on the statistical analyses consistent with the world health organization (who) standards.  dez river water quality has been “perfect” in most cases (99.8% of the statistical periods) on the basis of tds and average sum of them amounting to 644 mg/l; indeed only in 2% of the statistical periods the water quality has been determined as acceptable, while most of the water quality parameters have been within the permissible range of the who standards.