Eurasia: warm climate zones and inland waters

Eurasia’s inland waters are divided into surface (rivers, lakes, glaciers, reservoirs, canals) and underground waters. Its rivers flow into five basins: the Arctic, Atlantic, Pacific and Indian oceans and the inland basin. The biggest, fullest rivers are in temperate and monsoon lands; dry lands have few rivers. The longest river is the Yangtze (about 6 300 km), followed by the Yellow River, Ob–Irtysh, Yenisei, Lena and Mekong; Europe’s longest river is the Volga (3 530 km). The Volga, Amu Darya and Syr Darya belong to the inland basin. Rivers are fed by rain, snow, ice and groundwater; Siberian rivers flood in spring and freeze for long in winter, monsoon rivers (Ganges, Mekong) are full in summer, and Central Asian rivers, fed by mountain snow and ice, are full in early summer. The world’s largest lake is the Caspian (about 371 000 km²) and the deepest is Baikal (1 642 m). Baikal and Issyk-Kul are tectonic, Sarez was formed behind a landslide dam, and Lake Geneva is of tectonic–glacial origin. The Fedchenko Glacier in the Pamirs (about 77 km) is one of Asia’s longest mountain glaciers. In the north permafrost is widespread, reaching up to 1 500 m thick towards the north. The Aral Sea was an inland lake, but because so much water was taken from the Amu Darya and Syr Darya it began to dry up from the 1960s; most of it has now dried and become the Aralkum desert, while part of the Northern Aral has been restored by a dam.