The main regularities in the hydrochemical regime of the Sivash Gulf under the conditions of its commercial use were revealed. The quantitative assessment of brine saturation with gypsum and halite was implemented within periods of one year and many years. The thermodynamic simulation of the process of isothermal evaporation from the Sea of Azov at a temperature of 25°C was performed. © 1998 MAHK Hayka/Interperiodica Publishing.