Estimation of the inflow to the Urmia lake by integrating the time series modeling and the basin's future simulation in two long and short term conditions

The Urmia lake is the largest and the most important lake in Iran and is one of the most valuable international hemispherical resources in the world. But the Lake has been gradually getting dried nowadays. If the Lake gets completely dried, irreparable environmental, economical, and social damages will be done in the region. So, finding a practical solution for saving the Urmia lake is crucial. In the present research, it has been tried to predict the inflows of the rivers leading to the Urmia lake, once based on the long term period’s recorded data and another time based on the recent dry period’s recorded data, by using autoregressive moving average (ARMA) time series models in order to exert the effects of the recent drought in the forecasted data. The ARMA models are developed in the MATLAB software. After calibration of the created models, the predicted discharges of the basin’s rivers were entered into the simulation model of MODSIM in order to estimate the water consumptions in the basin's future condition and finally the entering flows to the Urmia Lake in each of two forecasting scenarios. Results show that in each of two forecasting scenarios of long and short periods, the environmental water right of the lake wouldn’t be supplied totally. Also, if the agricultural water consumptions are reduced about 14% and 56% in long and short periods respectively, the lake’s water right will be completely supplied. In this study, solutions for supplying the environmental water right of the lake are presented and analyzed.