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China Terrain and Drainage
Terrain and vegetation vary greatly in China. Mountains, hills,
and highlands cover about 66 percent of the nation's territory,
impeding communication and leaving limited level land for
agriculture. Most ranges, including all the major ones, trend eastwest . In the southwest, the Himalayas and the Kunlun Mountains
enclose the Qing Zang Plateau, which encompasses most of Xizang
Autonomous Region (also known as Tibet) and part of Qinghai
Province. It is the most extensive plateau in the world, where
elevations average more than 4,000 meters above sea level and the
loftiest summits rise to more than 7,200 meters.
From the Qing Zang Plateau, other less-elevated highlands,
rugged east-west trending mountains, and plateaus interrupted by
deep depressions fan out to the north and east. A continental scarp
marks the eastern margin of this territory extending from the
Greater Hinggan Range in northeastern China, through the Taihang
Shan (a range of mountains overlooking the North China Plain) to
the eastern edge of the Yunnan-Guizhou Plateau in the south
(see
fig. 4). Virtually all of the low-lying areas of China--the regions
of dense population and intensive cultivation--are found east of
this scarp line.
East-west ranges include some of Asia's greatest mountains. In
addition to the Himalayas and the Kunlun Mountains, there are the
Gangdise Shan (Kailas) and the Tian Shan ranges. The latter stands
between two great basins, the massive Tarim Basin to the south and
the Junggar Basin to the north. Rich deposits of coal, oil, and
metallic ores lie in the Tian Shan area. The largest inland basin
in China, the Tarim Basin measures 1,500 kilometers from east to
west and 600 kilometers from north to south at its widest parts.
The Himalayas form a natural boundary on the southwest as the
Altai Mountains do on the northwest. Lesser ranges branch out, some
at sharp angles from the major ranges. The mountains give rise to
all the principal rivers.
The spine of the Kunlun Mountains separates into several
branches as it runs eastward from the Pamir Mountains. The
northernmost branches, the Altun Shan and the Qilian Shan, rim the
Qing Zang Plateau in west-central China and overlook the Qaidam
Basin, a sandy and swampy region containing many salt lakes. A
southern branch of the Kunlun Mountains divides the watersheds of
the Huang He and the Chang Jiang (Yangtze River). The Gansu
Corridor, west of the great bend in the Huang He, was traditionally
an important communications link with Central Asia.
North of the 3,300-kilometer-long Great Wall, between Gansu
Province on the west and the Greater Hinggan Range on the east,
lies the Nei Monggol Plateau, at an average elevation of 1,000
meters above sea level. The Yin Shan, a system of mountains with
average elevations of 1,400 meters, extends east-west through the
center of this vast desert steppe peneplain. To the south is the
largest loess plateau in the world, covering 600,000 square
kilometers in Shaanxi Province, parts of Gansu and Shanxi
provinces, and some of Ningxia-Hui Autonomous Region. Loess is a
yellowish soil blown in from the Nei Monggol deserts. The loose,
loamy material travels easily in the wind, and through the
centuries it has veneered the plateau and choked the Huang He with
silt.
Because the river level drops precipitously toward the North
China Plain, where it continues a sluggish course across the delta,
it transports a heavy load of sand and mud from the upper reaches,
much of which is deposited on the flat plain. The flow is channeled
mainly by constantly repaired manmade embankments; as a result the
river flows on a raised ridge fifty meters or more above the plain,
and waterlogging, floods, and course changes have recurred over the
centuries. Traditionally, rulers were judged by their concern for
or indifference to preservation of the embankments. In the modern
era, the new leadership has been deeply committed to dealing with
the problem and has undertaken extensive flood control and
conservation measures.
Flowing from its source in the Qing Zang highlands, the Huang
He courses toward the sea through the North China Plain, the
historic center of Chinese expansion and influence.
Han (see Glossary)
people have farmed the rich alluvial soils of the plain
since ancient times, constructing the Grand Canal for north-south
transport
(see The Imperial Era
, ch. 1). The plain itself is
actually a continuation of the Dongbei (Manchurian) Plain to the
northeast but is separated from it by the Bo Hai Gulf, an extension
of the Huang Hai (Yellow Sea).
Like other densely populated areas of China, the plain is
subject not only to floods but to earthquakes. For example, the
mining and industrial center of Tangshan, about 165 kilometers east
of Beijing, was leveled by an earthquake in July 1976 that
reportedly also killed 242,000 people and injured 164,000.
The Qin Ling mountain range, a continuation of the Kunlun
Mountains, divides the North China Plain from the Chang Jiang Delta
and is the major physiographic boundary between the two great parts
of China Proper (see Glossary).
It is in a sense a cultural
boundary as well, influencing the distribution of custom and
language. South of the Qin Ling divide are the densely populated
and highly developed areas of the lower and middle plains of the
Chang Jiang and, on its upper reaches, the Sichuan Basin, an area
encircled by a high barrier of mountain ranges.
The country's longest and most important waterway, the Chang
Jiang is navigable over much of its length and has a vast
hydroelectric potential. Rising on the Qing Zang Plateau, the Chang
Jiang traverses 6,300 kilometers through the heart of the country,
draining an area of 1.8 million square kilometers before emptying
into the East China Sea. The roughly 300 million people who live
along its middle and lower reaches cultivate a great rice- and
wheat-producing area. The Sichuan Basin, favored by a mild, humid
climate and a long growing season, produces a rich variety of
crops; it is also a leading silk-producing area and an important
industrial region with substantial mineral resources.
Second only to the Qin Ling as an internal boundary is the Nan
Ling, the southernmost of the east-west mountain ranges. The Nan
Ling overlooks the part of China where a tropical climate permits
two crops of rice to be grown each year. Southeast of the mountains
lies a coastal, hilly region of small deltas and narrow valley
plains; the drainage area of the Zhu Jiang (Pearl River) and its
associated network of rivers occupies much of the region to the
south. West of the Nan Ling, the Yunnan-Guizhou Plateau rises in
two steps, averaging 1,200 and 1,800 meters in elevation,
respectively, toward the precipitous mountain regions of the
eastern Qing Zang Plateau.
The Hai He, like the Zhu Jiang and other major waterways, flows
from west to east. Its upper course consists of five rivers that
converge near Tianjin, then flow seventy kilometers before emptying
into the Bo Hai Gulf. Another major river, the Huai He, rises in
Henan Province and flows through several lakes before joining the
Chang Jiang near Yangzhou.
Inland drainage involving a number of upland basins in the
north and northeast accounts for about 40 percent of the country's
total drainage area. Many rivers and streams flow into lakes or
diminish in the desert. Some are useful for irrigation.
China's extensive territorial waters are principally marginal
seas of the western Pacific Ocean; these waters wash the shores of
a long and much-indented coastline and approximately 5,000 islands.
The Yellow, East China, and South China seas, too, are marginal
seas of the Pacific Ocean. More than half the coastline
(predominantly in the south) is rocky; most of the remainder is
sandy. The Bay of Hangzhou roughly divides the two kinds of
shoreline.
Data as of July 1987
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