Application of Time Series Analysis in Anticipation Brine Evolution in the Urmia Lake

From 2007 to 2015, over the course of nine years, 180 water samples were analyzed. The present study plans to predict the values of ions lake Urmia with using statistical methods ARIMA for the next six years. The most important purpose of time-series analysis is finding the trends of changes and prediction the future based on measurements from previous years. At first, the data was tested to evaluate the stationary then their non-stationary was removed by creating order in series. Finally ARIMA (1,1,0) was used to predict the K, Na, CO3 and Cl and ARIMA (0,1,1) for Mg, Ca and HCO3. The results show the lake Urmia brine types was Na-Mg-Cl until 2010 and it is on III path in the Eugster and Hardie flow diagram. It is comparable to Great salt lake in USA. Because of drying of lake Urima and enhancement of the water EVAPORATION rate to the dozens of times and also reducing the amount of surface water in recent years this trend is changed to Mg-Na-Cl type. It is predicted that the brine will have Mg-SO4-Cl type in 2021. It corresponds to the IIIB1b path in Eugster and Hardie brine evolution flow diagram.