The problem of the Aral Sea is an example of ecological hazards caused by the human activity. In the 1960-s, the intensive use of water from the Amu-Darya and the Syr-Darya for irrigation changed the water balance in the Aral Sea resulting in the excess the evaporation over the precipitation and the river runoff. In 1989, this caused separation of the Northern and the Central Aral basins, and in 2000, the connection of the Lazarev, the Vozrojdenija islands with the mainland and the formation of a single Peninsula separating the Western (deep) and the Eastern (shallow) basins with connection only in the Northern part. As a result, the Aral Sea level height decreased from 53 to 32.5 m (in the Baltic system), has lost 80 % of water volume and 60 % of the sea surface. The salinity increased from 10 to 68-70 g/l thus destroying the fishing industry. The ecological and social consequences are also dramatic. This work is done under the support of the INTAS Grant 01-0511-REBASOWS. Objectives of the research are as follows: forecasting the future Aral Sea water and salt balance under different scenarios of the water inflow to the Aral coastal zone; definition of a sustainable ecological profile of a closed water body and selection of a strategy of a possible ecosystem, biodiversity and bioproductivity restoration in a part of the Aral Sea.
Possible ways for rehabilitation of the Aral Sea are as follows:
- Reducing up to 70 % of the Amu-Darya water for irrigation, which would increase the Aral Sea level up to 38.5 m (an unrealistic version);
- Separation of the Western and Eastern parts and keeping only one of them with 20-35 % reduction of water for irrigation.
In this paper, some results of the numerical modeling of the Aral Sea circulation as well as demineralization during a high-water period of 1998 are presented. The 3D model used in the numerical experiment is the Novosibirsk Computing Center (now the ICM&MG) ocean circulation model adapted to the Aral Sea basin.