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close this bookCentral Eurasian Water Crisis: Caspian, Aral, and Dead Seas (UNU, 1998, 203 pages)
close this folderPart III: The Caspian Sea
close this folder8. Environmental policy-making for sustainable development of the Caspian Sea area
View the document(introductory text...)
View the documentIntroduction
View the documentMorphometry and the principal hydrological features
View the documentThe water balance and water-level variations
View the documentThe economic impacts on the Caspian states of the water-level variations
View the documentOther development issues requiring international cooperation
View the documentConclusions
View the documentAcknowledgement
View the documentReferences

Morphometry and the principal hydrological features

The Caspian Sea is so large that it really deserves to be called a Sea. Its area is about 400,000 km2, it is 1,200 km long and 170-450 km wide, and its water volume is 80,000 km3. The total length of the shoreline is about 7,000 km. The average depth is 180 m and its maximum depth is 1,025 m. All these data are approximate, because they vary considerably depending on the water level of the Sea.

Morphologically, the Caspian Sea is divided into three main parts, which are more or less equal in area: a very shallow northern part with depths not exceeding 10 m, a middle part with an average depth of 170 m and a maximum depth of 790 m, and the deepest southern part, which has an average depth of 325 m and a maximum depth of 1,025 m (Avakian and Shirokov, 1994). The proportional volumes of the three parts are correspondingly 1/100, 1/3, and 2/3 of the total volume. The salinity of the Caspian Sea water ranges between 0.2 g/litre at the mouth of the Volga to 12-13 g/litre in the central and southern parts.

Because of its relatively small volume and depth, the northern part is the most vulnerable hydrologically and, hence, ecologically and economically. In addition, the shores of the northern part are as flat as its bottom and therefore the shoreline looks very insignificant. The shoreline is very variable, depending on both (a) the longer-term, climate-induced variations in water level of the Sea as a whole and (b) short-term, local wind action. A typical situation would be a rapid increase in sealevel, usually in the cold part of the year, as a result of strong winds, mostly from a southerly direction. In the most catastrophic cases the water level increases by 3.0-4.5 m and, owing to the flat topography, the Sea penetrates far inland, inundating strips 30-50 km wide for a few hundred kilometres along the coast. During the wind-driven waves of 11-13 November 1952 the inundation covered about 17,000 km2. In such cases the damage to settlements, roads, oil installations, etc. is very high.

The latest example of wind-driven catastrophic inundation was reported in the press as this chapter was being prepared. During 1216 March 1995 in Kalmykia, an Autonomous Republic of the Russian Federation situated on the north-western coast of the Caspian Sea, the water level increased up to 3 m. Over 200,000 hectares (2,000 km2) were inundated. Losses of human life were recorded (the exact figure was not given), and 520 houses (home to 3,200 people) were destroyed. About 150,000 sheep were lost.

The Caspian Sea is a closed water body. The main tributary, the Volga, is the largest river of Europe. Its watershed area is 1,360,000 km2 or about 40 per cent of the total for the Caspian, but it brings over 80 per cent of the total surface and underground flow to the Sea. From various points of view, the Volga plays a very important role in the state of the Caspian Sea with regard to its water balance, oscillations in its water level, and its chemical and biological make-up. Through these factors the Volga influences the socioeconomic development of the Sea and the adjacent territories.

The Volga River basin belongs completely to the Russian Federation. It contains about 40 per cent of Russia's population and is responsible for one-third of both the industrial and agricultural production of Russia. Psychologically, the river is viewed as "Mother Volga," the nation's main river. An integrated, sustainable environmental management for the Caspian Sea is impossible without a proper programme of action for the Volga basin. Such a programme would extend international cooperation on the Caspian deep inside Russia to Moscow.