Chinese Topography (Stereoscopic)

Author: Compiled by the Institute of Cartographic Science
Publisher:
Publish Date: 2001-10-01
Features: The topography of China is characterized by the following aspects:
1. West-high and east-low, with a step-like distribution: The Yellow River and Yangtze River, both originating from the Qinghai-Tibet Plateau in the west, flow eastward through nine or ten provinces, municipalities, and autonomous regions before emptying into the Bohai Sea and the East China Sea. The general flow direction of China's major rivers reflects the overall topographical trend of west-high and east-low. China's topography not only trends west-high and east-low but also features various topographical types that roughly surround the Qinghai-Tibet Plateau, known as the "Roof of the World," in a semi-circular step-like manner toward the Pacific Ocean. The topographical boundary, formed by two mountain ranges, distinctly divides the continental topography into three steps. The Qinghai-Tibet Plateau has an average elevation of over 4,000 meters, covering an area of 2.3 million square kilometers, making it one of the largest plateaus in the world and the highest step in China's topography. It dominates the southwest, with a series of snow-capped mountain ranges stretching across the plateau from north to south, including the Kunlun Mountains, Altun Mountains, Qilian Mountains, Tanggula Mountains, Karakoram Mountains, Gangdise Mountains, and Himalayas. Among the mountain ranges of the plateau, there are numerous large and small basins with rich grasslands and shimmering lakes. This region also holds abundant resources waiting to be developed. Crossing the northern edge of the Kunlun Mountains-Qilian Mountains and the eastern edge of the Min Mountains-Qionglai Mountains-Hengduan Mountains, the terrain drops rapidly to an altitude of about 1,000 to 2,000 meters, with some areas as low as below 500 meters—this is the second step. Its eastern edge is roughly defined by the Greater Khingan Mountains to the Taihang Mountains, extending southward through the Wushan Mountains to the Wuling Mountains and Xuefeng Mountains. Here, a series of high mountains, plateaus, and basins with elevations above 1,500 meters are distributed, including the Altai Mountains, Tian Shan Mountains, Qinling Mountains; the Inner Mongolian Plateau, Loess Plateau, and Yunnan-Guizhou Plateau; the Junggar Basin, Tarim Basin, Qaidam Basin, and Sichuan Basin. Beyond the Greater Khingan Mountains to the Xuefeng Mountains, eastward to the coast, there is a region of hills and plains with elevations below 500 meters, which can be considered the third step. In this step, from north to south, there are the Northeast Plain, North China Plain, and Middle-Lower Yangtze Plain; to the south of the Yangtze River, there is a vast area of low mountains and hills generally referred to as the Southeast Hills. The former have elevations below 200 meters, while the latter mostly range between 200 and 500 meters, with only a few mountain ranges reaching or exceeding 1,000 meters. From the coastline eastward, there is an endless expanse of shallow seas with depths generally less than 200 meters, dotted with islands. Some also consider this as the fourth step of China's topography. In terms of land topography, two boundaries and three steps gradually descend from west to east, roughly outlining the overall profile of China's topography. This step-like topographical pattern is reflected in the topographical profiles along China's 89° east longitude line and 30° north latitude line. China's topographical characteristics of being west-high and east-low, facing the ocean in a step-like manner, not only facilitates the penetration of warm and humid maritime air currents from the southeast into the interior, profoundly influencing China's climate in a positive way but also ensures sufficient precipitation in the eastern plains and hilly regions, especially during the periods of peak precipitation and high temperatures, providing、 conditions for the development of agricultural production; but also allows the main rivers on the continent to flow eastward into the sea, making it easier to connect China's land and sea transportation and facilitating economic and trade exchanges between China's eastern and western regions; at the same time, this step-like topography also influences rivers to form significant multi-level drops, thereby storing enormous hydropower resources suitable for multi-level development.
2. Diverse Morphology, Vast Mountainous Areas
China's topographical types are diverse and rich in variety, whether viewed from their formation or morphology. There are high plateaus and mountains uplifted by internal forces, as well as low-lying basins and plains subsided by folding. In the warm and humid eastern and southern regions, there are various erosion and accumulation landforms dominated by fluvial processes; in the arid northwest, there are desert landscapes dominated by wind erosion; on the western high mountains, there are distinctive glacial landforms; and in the southwestern limestone distribution areas, there are scenic karst landscapes. The Qinghai-Tibet Plateau, Yunnan-Guizhou Plateau, Inner Mongolian Plateau, and Loess Plateau are China's four famous plateaus. The Tarim Basin, Junggar Basin, Qaidam Basin, and Sichuan Basin are China's four famous basins. Major rivers such as the Yangtze, Yellow River, Pearl River, and Heilongjiang flow across the vast land, creating many extensive and fertile plains. On these plains, lush low mountains and hills are scattered, while in the west, there are countless towering and rugged mountains. Diverse topography provides extremely favorable conditions for the comprehensive development of agriculture, forestry, animal husbandry, sideline industries, and fishery industries. Statistics show that mountains and hills account for about 43% of China's total land area, plateaus for 26%, basins for 19%, and plains for 12%. If high mountains, medium mountains, low mountains, hills, and rugged plateaus are all included, then China's mountainous areas account for more than two-thirds of the country's total land area. Although mountainous areas are not conducive to the development of agriculture, transportation, and economic and cultural exchanges, they are rich in mineral resources, dense forests, and precious plant and animal resources, which are invaluable assets for China's socialist construction.
3. Interweaving Mountain Ranges with Oriented Arrangement
China is a mountainous country, not only with vast mountainous areas but also with large and small mountain ranges crisscrossing the nation in an orderly and oriented arrangement, primarily in east-west and northeast-southwest directions, with fewer in northwest-southeast and north-south directions. The east-west mountain ranges consist of three major rows: the northernmost is the Tian Shan-Yinshan, the middle is the Kunlun Mountains-Qinling Mountains, and the southernmost is the Nanling Mountains. The northeast-southwest mountain ranges are mostly distributed in the east, with lower elevations. There are also three major rows of these mountain ranges: the westernmost is the Greater Khingan Mountains-Taihang Mountains-Wushan Mountains-Wuling Mountains-Xuefeng Mountains, which is the boundary between the second and third steps mentioned earlier; the middle row includes Changbai Mountains, Liaodong Hills, Shandong Hills, and the southeastern hilly mountains in Zhejiang and Fujian; the easternmost is the Taiwan Mountains rising from the sea. The northwest-southeast mountain ranges are mostly distributed in the west, in order from north to south: Altai Mountains, Qilian Mountains, and Himalayas. The north-south mountain ranges run through the central part of China, mainly including the Helan Mountains, Liupan Mountains, and Hengduan Mountains. These mountain ranges form the skeleton of China's topography, dividing the land into many grids. The outlines of plateaus, basins, plains, inland seas, and marginal seas within these grids are influenced to some extent by these mountain ranges. The east-west mountain ranges across the country also serve as water divides for major rivers. The Qinling Mountains are the water divide between the Yellow River and the Yangtze River, while the Nanling Mountains are the water divide between the Yangtze River and the Pearl River. The flow direction of rivers is clearly constrained by mountain ranges. For example, rivers in the southwest such as the Yarlung Zangbo River, Jinsha River, Lancang River, and Nujiang River are controlled by mountain ranges such as the Gangdise Mountains, Tanggula Mountains, Himalayas, and Hengduan Mountains. The general flow direction of the Yangtze and Yellow Rivers is from west to east, but many sections are also influenced by mountain ranges, varying in width and sometimes flowing southeastward or northeastward before eventually emptying into the sea. In addition to these three major characteristics, from a structural perspective, China's topographical features can be summarized in four aspects: three longitudinal mountain belts, three marginal Pacific mountain ranges, two large-scale depressions with specific orientations, and a large arcuate mountain range.
The three longitudinal mountain belts refer to the three east-west mountain systems mentioned earlier, composed of numerous mountain ranges. The intervals between them are almost 8 to 10 degrees of latitude. For example, the main body of the Tian Shan-Yinshan is located roughly between 40°30′N and 42°30′N; the main body of the Kunlun Mountains-Qinling Mountains is located roughly between 32°30′N and 34°30′N; and the main body of the Nanling Mountains is located roughly between 24°00′N and 25°30′N. These three longitudinal mountain belts actually form three important geographical boundaries in China, which have a significant impact on China's climate, hydrology, and agricultural production, among other aspects.
The three marginal Pacific mountain ranges refer to the three northeast-southwest mountain ranges in eastern China, arranged like geese in flight. They are almost three parallel belt-like mountain ranges: the easternmost is the Taiwan Mountains, the middle is the Changbai Mountains-Zhejiang-Fujian hills, and the westernmost is the Greater Khingan Mountains-Xuefeng Mountains. Since their positions are almost perpendicular to China's prevailing southeast monsoon, they enhance the climatic characteristics of moist conditions in the east and arid conditions in the west. This effect is particularly evident in the Greater Khingan Mountains, where erosion prevails to the east of the range, while dry denudation dominates to the west.
The two large-scale depressions with specific orientations refer to the northeast-southwest trending subsidence belts in eastern China, composed of the Northeast Plain, North China Plain, and Middle-Lower Yangtze Plain, and another subsidence belt in the central part of China, consisting of the Hulunbuir Basin to the west of the Greater Khingan Mountains, the Shaanxi-Gansu-Ningxia Basin, and the Sichuan Basin. The sides of these subsidence belts are corresponding uplift belts. In northwestern China, there is another group of three large basins nearly parallel to the east-west mountain systems: the Junggar Basin, Tarim Basin, and Qaidam Basin. They also reflect the alternating characteristics of subsidence belts and uplift belts. This alternating phenomenon of subsidence belts and uplift belts further illustrates the internal connections between different topographical features, indicating that subsidence and uplift, depression and uplift are a pair of opposing yet complementary contradictions in nature. The existence and discovery of this phenomenon have great practical significance. Because in the subsidence belts and uplift belts of the Xinhuaxia system in eastern China, there are many basins separated by east-west structural systems, which are ideal oil-bearing basins. As early as the 1950s, Li Siguang, based on the theory of geomechanics, pointed out that these subsidence belts definitely contained oil and identified the Songliao Plain, North China Plain, Sichuan Basin, and Shaanxi-Gansu-Ningxia Basin as promising areas for oil exploration. Li Siguang's scientific conclusion has been verified by practice.
The large arcuate mountain range mainly refers to the mountain belt in the southwest, composed of the Himalayas, Gangdise Mountains, Tanggula Mountains, Daxue Mountains, and Hengduan Mountains, which rise majestically above the Qinghai-Tibet Plateau, forming the most magnificent and towering mountain range in the world. The formation of this high mountain belt is mainly due to the collision of the Indian subcontinent's continental crust with the Asian continent, causing the crust to slide along the continental base. As a result, the Qinghai-Tibet Plateau has been gradually uplifted and clearly exhibits the thickness of two continents. This concept has been supported by seismic evidence.
Huaxia tectonics and Xinhuaxia tectonics are names of tectonic systems within the twist tectonic system of geomechanics. The Huaxia tectonic system is a set of compression zones close to 45° northeast. The Xinhuaxia tectonic system is a set of compression zones in the direction of north-northeast, widely distributed in eastern China, forming three uplift belts and three subsidence belts from east to west, essentially a large-scale multi-character tectonic system.