The territory of the China is largely mountainous (over 3/4 of the surface), and is characterized by a succession of high lands, sloping from W to East up to the eastern, hilly and flat sublittoral belt. The highest regions are mostly made up of plateaus, generally bordered by mountain ranges that branch off from the Pamir first in the NE and E-SE direction, giving rise to a series of secondary reliefs that come to affect the coastal strip.
According to LOVERISTS.COM, the highest area corresponds to the Tibetan plateau (4000 m asl on average), divided between the autonomous region of Tibet (Xizang) and Qinghai; the plateau is circumscribed to the West by the Karakoram, to the S by the Himalayas (where are the highest elevations of the country, and of the whole Earth, over 8000 m) and to the North by the chain of the Kunlun mountains (over 7000 m of altitude), from the basin of Tsaidam (Qaidam) and, further to the outside, from the Altun and Qilian mountains (which exceed 5000 m); these, bending towards S and joining with the eastern offshoots of the Himalayas, give rise to a series of long subparallel chains (with NS direction and peaks over 6000-7000 m), deeply engraved by river valleys (Nu-Salween, Lancang-Mekong, Chang Jiang etc.), affecting a large part of Sichuan and all of Yunnan, then continuing into Indochina.
AN of Tibet extend the lower (1000-2000 m) plateaus of Xinjiang Uygur and Zungaria, divided by the Tian Shan chain (with elevations of 5000-7000 m); the Zungaria is in turn closed to the North by the southern reaches of Altaj, while to the East it merges with the north-eastern extremity of Xinjiang and therefore with the plateau of Inner Mongolia, which stretches for about 3000 km and is in much of it occupied by the Gobi desert. The relief then slopes down into a wide hilly belt, both to the S of Inner Mongolia, up to the Bay of Liaodong (Yellow Sea), immediately N of Beijing, and to the East and SE of the reliefs that embrace Tibet, almost reaching the shores of the Gulf of Tonkin; this belt, of modest elevation, but locally reinforced by chains (Qin Ling, Daba Shan and others) which also reach considerable altitudes, is interrupted by the great river valleys that here descend from the W to the E, first of all those of the Huang He (Yellow River) and the Chang Jiang (improperly called the Blue River), and by the wide plain corresponding to the high sinking basin of this ‘last, in the eastern section of Sichuan. AS del Chang Jiang other hill formations extend in the E direction, up to the coasts of the Strait of Formosa and the East China Sea.
AE and NE of Inner Mongolia, mountain ranges (Great and Little Khingan, not very high), along the border with Mongolia and Russia, and rather extensive hill formations, N of the Korean peninsula, embrace the wide and fertile North China Lowlands (wholesale correspondent to Manchuria), which pushes its black lands to the sea at Liaodong Bay. Further south, beyond the hills that encircle the Beijing region from the north, extends the much larger southern Chinese lowland, which essentially corresponds to the low valleys of Huang He and Chang Jiang; to the South of the latter the plain is interrupted and then replaced by the hill formations mentioned above, in the provinces of Zhejiang and Fujian. Other large areas of the plain open up even more to the South, along the Gulf of Tonkin and the South China Sea, in Guanxi and Guangdong. A traditional distinction divides China proper into China Northern and China Southern, corresponding to the North and S regions of Huang He respectively.
The mountain systems of northern China, mostly of very ancient origin, have been subjected to severe erosion and give the region, with the plateaus from which they are detached, a uniform general appearance. The river valleys are deep and with steep walls, interrupted by basins covered by löss, that is, by deposits, which can reach a few hundred meters thick, of dust from the steppes and deserts of Central Asia, carried by the wind and therefore by rivers that filled the Chinese lowlands. This is extremely fertile, densely populated and cultivated, crossed by a dense network of irrigation and navigable canals, including the Imperial Canal, which from Tianjin reaches Hangzhou with a course of 1100 km parallel to the coast.
In southern China, the arrangement of the mountainous and hilly systems has led to the formation of a large number of extremely fertile basins: among these, the sinking basin, called the Central Plain, of the middle Chang Jiang, and the ‘red basin’ of Sichuan, so called from the color of its sandstones, regions of particular population density. In contrast, the western part of the country, sometimes called China external or simply western, has a much more modest population, certainly discouraged by the environmental conditions, largely dominated by high reliefs, closed basins and sub-desert or desert plateaus.