ABSTRACT
Water use is determined primarily by the availability of water resources which are unevenly distributed in the former USSR (Table 3.1). The majority of river water (86.5 per cent) flows in northern and eastern areas and in the Arctic Ocean and Pacific Ocean basins. Only 13.5 per cent of river water resources are located in the most populated and economically developed western and southern regions, draining into the Atlantic Ocean and the Aral and Caspian Seas. According to water resource availability, the former USSR can be divided into three zones: zones of high water availability, zones of intermediate water availability, and zones of insufficient water availability. The zones with insufficient water availability comprise more than 25 per cent of the territory, including Southern Ukraine, Moldova, middle and lower reaches of the River Volga, the Caspian lowland, southern parts of West Siberia, Kazakhstan and the Turkmenistan lowland amongst others. Only 2 per cent of total water resources are found in these territories. Among the Republics of the former USSR, the territory of the Russian Federation, Latvia, Estonia and Lithuania have a considerable part of their territory in the zone of high water availability. Economic development in water catchment areas has led to changes in surface runoff, water balance and flow regime. The most noticeable alterations occurred in the 1950s and 1960s.
