Glacial Meltwater Resources in China

Abstract

IT is claimed that the average amount of glacial meltwater in the rivers of Central Asia is as high as thirty to forty per ce t, although so hydrologists, including V. L. Shul'ts, believe that glaciers contribute only ten per cent to the stream flow. Artificial methods for increasing this contribution have been known for many cen? turies. The inhabitants of mountainous Tadzhikistan, for instance, have for long scattered earth and ashes over snow in order to quicken melting, and this method is described in the accounts of the campaigns of Alexander the Great (Avsyuk, 1963). Owing to the contemporary importance of the development of Russia's eastern territories, economically necessary to provide agricultural produce and extend industry's areal base and, as the Sino-Soviet rift deepens, strategically necessary because of the increasing power of China, extensive research into the utilization of glacial resources has been carried on in the Soviet Union, especially during the 1950's and early 6o's. Since 1959 similar experiments on a semi-commercial scale have been undertaken in China, in an attempt to provide something of a successful counterpart to Khrushchev's Virgin Lands. China has an estimated 44,000 square kilometres of glacial and perennial snowcovered areas. With a total water reserve of 240,000 million cubic metres, these areas account for one-third of the glacial areas in the temperate and tropical zones of the world (NCNA, Lanchow). In view of these vital statistics, and as half of China's glacial area is situated in the arid expanses of north-west China (a region which has constantly provided a challenge to settlement in times of strong central government and especially today, when China has a population of 750 million expanding at a rate of about 15 million a year) (Freeberne, 1964), the Government attaches a priority to the research into and development of glacial meltwater resources. Glaciers in the Kilien and Tienshan Mountains feed most of the rivers of north? west China, and account for as much as fifty to seventy per cent of the stream flow of some of the rivers (NCNA, Lanchow). The Sinkiang Uighur Autonomous Region is the scene of the most intensive Chinese efforts in the utilization of glacial melt? water. Whereas Sinkiang enjoys a sunny climate with a long frost-free period, it suffers from extreme aridity. * Annual rainfall averages 60 mm. while evaporation rises as high as 2000 mm. a year. In some parts the raindrops often evaporate before they touch the ground' (Peking Rev., 1963). Water supply from the melting snows during summer is critical, therefore, to the success of agriculture which is on a limited, though expanding scale. Before 1949 the area of cultivated land in Sinkiang was as little as 18 million mow,1 and it was necessary to import grain. Although the popula? tion has more than doubled since 1949,3 the region is now self-sufficient in food grain. * This phenomenal change was made possible mainly by enlarging and rationalizing the supply of water' (Peking Rev., 1963). The utilization of glacial meltwater is but one element in a complex which has included the diversion of rivers, and the construction of over 200 reservoirs, as well as canals and irrigation ditches, together making possible an extension of cultivable land to cover an area of more than 46 mil? lion mow.