عنوان مقاله [English]
In this study, the trend of water quality variables of Sosan and Gotvand hydrometer stations were estimated to evaluation the effectives of Gotvand's dam on Karoon River. The water quality variables are TDS, EC, pH and SAR in period of 1998 to 2012. The results of modified Mann-Kendall test for Sosan station showed that the TDS variable was seen the increasing and decreasing trend in monthly scale. Between all months, the August has the most significant increasing trend in TDS variable and with attention to the calculated the Sen slope, this variable was increased about 180.32 (mg/l) in resent 16 years. In annual scale, also the trend of TDS was calculated as non-significant increasing. Also the trend of EC variable in Sosan station was same as TDS and has a non-significant increasing trend in most of months. In annual scale also was seen the increasing trend in EC variable. GThe results of modified Mann-Kendall test for Gotvand station showed the decreasing trend in the water quality of Karon River after the Gotvand's dam. TDS variable has a increasing and decreasing trend in Gotvand station in monthly scale. EC variable in Gotvand station in all of months has a increasing trend. The results of evaluation the time of changing trend showed that the most significant failure occurred in year 2007. The results of chemical analysis of water quality in the Karun River gauging stations showed that from 2001 to 21013 the values of EC were increased about 160 percent.