W

Water balance of the Aral Sea – the water balance of the sea depends on the correlation between the inflow of river and groundwaters, atmospheric precipitation, and water losses to evaporation. The structure of the A.S. water balance is a function of various levels of economic development. From 1930 through 1990, the available water resources in the basin were estimated at 115 cu. km annually. Natural water losses in 1930 were 36 cu. km, in 1960 – 13 cu. km, and in 1990 – 7 cu. km. Water consumption in 1930 was 25 cu. km, in 1960 – 48 cu. km, and in 1990 – 103 cu. km. Water inflow into A.S. in the period from 1930 to 1960 was 54 cu. km, while in 1990 it was 5 cu. km. The reduced water inflow was caused by flow regulation with reservoirs and diversion of excess waters into deserts for irrigation; drainage waters did not return into rivers. Since 1961, the water level has dropped by 23.6 m, which has led to disastrous socioeconomic consequences for the population, numbering an estimated 3 mln people, in the Circum-Aral area. TheWB that was earlier nearly at equilibrium is now characterized by deficit.