Application of SALTMED Model for Prediction of the Salinity of Karkheh River After Implementation of the First Phase of 550,000 hectare Land Reclamation Project in Khuzestan and Ilam Provinces

In this study, salinity prediction of Karkheh River after exploitation of irrigation and drainage projects of Jahad Nasr Institute was investigated using SALTMED salinity simulator model. Due to climatic conditions, cultivation pattern, irrigation schedule, soil and water characteristics and drainage of the Evan, Dowsalagh, Arayez and Bagheh plains that are excluding the Upper Plains, the volume of drainage output and the amount of salt produced from each plain with a total area of 55,000 hectares were simulated. Also from the data, the years (2013-2017) were used due to completeness of the information. The results showed that based on the prediction of the SALTMED model in the statistical year 2013; the amount of 150, 87, 140 and 197 thousand tons of salts enter the Karkheh River annually from the Evan Plain, Dowsalagh, Arayez and Bagheh, respectively. If the same trend continues for 10 years, an amount of 5.74 million tons of salt will enter Karkheh and then eventually discharge into the Hawizeh Marshes, which will have many environmental impacts. The overall result showed that by exploiting 37,000 hectares of 55,000 hectares in the four plains, the Karkheh water salinity index (EC) increased significantly and on average, it will reach from 1.15 dS/m to more than 2 dS/m. Now, if all 55,000 hectares or more of the 550,000 hectares of land were exploited, how much salt and drainage water would flow into the rivers?