The great mountainous belt that crosses the continent is at the basis not only of the main structural and morphological divisions but also consequently of hydrography. It clearly divides the main basins of the continent, tributaries of the Pacific Ocean (23% of the total area), the Indian Ocean (18%) and the Arctic Ocean (27%). In its vastness, however, Asia also occupies extensive closed basins, corresponding to the large internal depressions that are generally found in the immediate vicinity of the mountain range: the main ones are those of Central Asia (Aralo-Caspian basin), Eastern Turkestan, Zungaria and Mongolia, the Tibet plateau, as well as those of the Iranian plateau (Sīstān, Lut etc.) and Anatolia. In these basins, which cover approx. Helmand, Amudar’ja, Tarim etc.) fed by the mountainous belt that goes from Anatolia to China; however the major rivers that arise from the same strip reach the sea and with their great development and their gigantic flows are as many arteries of life, especially those that drain southern Asia featured by COUNTRYAAH.COM. This to an extent and in a way that have no parallel in other parts of the world, if we exclude the Nile. They are in fact great axes of human attraction and civilization, which have also become such because they cross arid or semi-arid regions or alternate seasons. These historic rivers, the foundation of all Asian geography, follow one another from W to E at the foot of the great chains. The Tigris and the Euphrates, which with their floods created the Mesopotamian plain and fueled the life of the region; from the mountains of Tibet originates the Indus, which formed the vast plain of Pakistan, seat of ancient civilization; the Ganges originates from the Himalayas, revitalizing the plain between the great mountain barrier and the Deccan and joining at the mouth with the Brahmaputra, forming an extensive delta area. The rivers that make up the mighty arteries of the Indochinese peninsula, such as the Mekong, arise from the Tibetan valleys converging towards the SE, while the great Chinese rivers, Chang Jiang and Huang He, come to life from the easternmost ones., which were at the origin of Chinese civilization. All these rivers, like the others that run out in the endorheic areas, have variable seasonal flows in relation to both rainfall which, especially in monsoon Asia, are highly concentrated, giving rise to large floods, and feeding from snow. The breadth of their basins mostly ensures considerable flow rates in every season of the year.
Their course still generally has a youthful profile and in relation to this they have a notable detrital transport; a separate case is that of Huang He, which was born in a region in löss subject to severe accelerated erosion, to which agricultural exploitation also contributed; today, however, the basin of this river has been regulated and thus the gigantic floods which it periodically gave rise to have been avoided. The rivers that carry their course towards the N are of less importance from the anthropic point of view, although they are no less gigantic than those of the southern side of Asia. Overall, they do not have large flows, because rainfall is reduced due to the continental nature of the climate; their regime is largely nival, characterized by the peculiarity of the non-simultaneous melting of the ice, which occurs in successive times proceeding from S to N and is therefore the cause of regular flooding in the vast Siberian lowlands. All Arctic rivers are very long, with a mature course, and this in relation to the structure and morphology of the vast Siberian region. The Ob – Irtyš, which crosses the great Western Lowland, the Enisej, which with a spring branch, the Angara, draws on Lake Baikal, then the Lena, the Kolyma and other minor ones. The Amur is also an important river, which however flows into the Sea of Okhotsk and is therefore a tributary of the Pacific. As for the lakes, they are located, as already mentioned, in inland areas, depression: the largest are the Caspian Sea and the Aral Sea., once united to form a sort of inland sea and today in a gradual phase of reduction. Endorheic are the numerous lakes of the Tibetan plateau and those of Turkestan tectonic origin, such as Balhaš. Baikal, a majestic example of a fracture lake, is the deepest (over 1620m) on Earth.
