Print  Font Size: 

Exterior Rivers

Practically all the large rivers in China belong to the exterior river system, directly or indirectly emptying into the seas. Because China’s terrain is high in the west and low in the east, most of its rivers flow westeast into the Pacific, including the Heilong, Liaohe, Haihe, Huanghe, Huaihe, Changjiang (Yangtze River), Minjiang, Zhujiang and Lancang rivers. The area drained by these rivers belongs to the Pacific catchment area, and covers 5.4459 million square kilometers, or 56.8 percent of the country’s total area and 88.9 percent of the exterior drainage area. The Nujiang and Yarlungzangbo rivers in the south of the Qinghai-Tibet Plateau, which flow south out of China into the Indian Ocean, have a catchment area of 624,500 square kilometers in China, or 6.5 percent of its total area. The Eirtix in the northwest corner of Xinjiang, which flows north out of china into the Arctic Ocean, drains 50,000 square kilometers, or 0.5 percent of the country’s total area.

The exterior river catchment area, the land surface that supplies these rivers with water, is 6.1213 million square kilometers, or 63.8 percent of the country’s total land mass, and is basically identical with the monsoon influenced regions. With abundant supply of water resulting from the plentiful precipitation there, the total flow of the exterior rivers makes up more than 95 percent of the total of the country’s rivers.

With the Qinling-Huaihe line as the divide, the exterior rivers south and north of it have their own distinctive characteristics.

The rivers south of the line, such as the Changjiang (Yangtze River), Qiantang, Minjiang and Zhujiang, are in the humid zone, where the rainy seasons long, annual precipitations plentiful, plant growth is luxuriant, water conservation is fine and the winter temperature is above 0° Centigrade. Therefore, these rivers have a large flow, many tributaries, long high-water season, small seasonal variation in water-level, small amounts of silt, and nonfreezing period.

The rivers to the north of this line, such as the Liaohe, Haihe and Huang he, are in the semi-humid and semi-arid zones, where the annual precipitation is small and concentrated in July and August, the vegetation is sparse, soil erosion is serious and the winter temperature is below zero Centigrade. Therefore, these rivers have a small flow, few tributaries short high-water season, big seasonal variation in water-level, a low-water period in winter, large amounts of silt, and a freezing period of varying lengths. All these characteristics are unfavorable to water conservation, power-generation, irrigation and navigation.

The Heilong River system and the Yalu River in the northeast have their special features. Characteristic of the rivers of the north, they freeze over for long periods in winter. On the other hand, because they flow across the humid, densely forested mountain areas, they carry heavy volume of water with little silt, which is characteristic of the rivers in the south.

The Nujiang and Lancang rivers bong to another type. Rising in the Qinghai-Tibet Plateau, they flow between towering mountains; their drainage basins are small and their tributaries are few. But because they are ice-free, carry little silt and have great drops in height, they have an enormous flow that offers an abundant source of power.

To do a quick search, highlighting any word(s) then click Help!