The Huai River (),
formerly romanized as the Hwai, is a major river in
China. It is located about midway between the
Yellow River and
Yangtze,
the two longest rivers and largest drainage basins in China, and like them runs from west to east. Historically draining directly into the
Yellow Sea, floods have changed the course of the river such that it now primarily discharges into the Yangtze. The Huai is notoriously vulnerable to flooding.
The
Qinling–Huaihe Line
The Qinling–Huaihe Line () is a reference line used by geographers to distinguish between northern and southern China, corresponding roughly to the 33rd parallel. Qinling refers to the Qin Mountains, and Huaihe refers to the Huai River. Runn ...
, formed by the Huai River and the
Qin Mountains, is sometimes regarded as the geographical dividing line between
Northern and southern China. This line approximates the January
isotherm and the
isohyet in China.
The Huai River is long with a drainage area of .
Course
The Huai River originates in Tongbai Mountain in
Henan province
Henan (; or ; ; alternatively Honan) is a landlocked province of China, in the central part of the country. Henan is often referred to as Zhongyuan or Zhongzhou (), which literally means "central plain" or "midland", although the name is al ...
. It flows through southern Henan, northern
Anhui, and northern
Jiangsu where it pools into
Lake Hongze.
Nowadays the Huai River then runs southwards as the Sanhe River by way of the
Gaoyou Lake
Gaoyou Lake () is the sixth largest freshwater lake in China, it is located between Anhui Province and Jiangsu Province. In a sense Gaoyou Lake is a manmade lake, and its creation is part of a long story about flood control and hydraulic engineerin ...
and
Shaobo Lake
Shaobo Lake () is a freshwater lake in Jiangsu Province, China, it is located between Gaoyou and Yangzhou. Shaobo Lake is a part of the Huai River system as the Huai River flows south through Shaobo Lake on its way to the Yangtze River like Gaoyo ...
emptying into Yangtze River at Sanjiangying (三江营) near
Yangzhou.
There is also a passage called the
Huaihe Sea Entryway and Subei Irrigation Canal that passes
Huai'an empties into the sea at Biandan Port. A separate course runs north by way of the Huaimu River and Huai Shu River and connects the Huai River system with the Xinyi River (part of the Yishusi River system) which exits into the sea at
Guanyun in
Lianyungang.
In part to circumvent flooding, in
Jiangsu province the Huai river system is interconnected with different waterways and thereby forms part of the
Grand Canal.
History
Historically, the Huai River entered the
Yellow Sea at
Yunti Pass (modern day Yunti Village, in Huangwei Town of
Xiangshui County) through a broad and level lower course. It was long used to irrigate the surrounding farmlands, and was the center of an extensive network of canals and tributaries.
Beginning in 1194, however, the
Yellow River to the north repeatedly changed its course southwards to run into the Huai River. The resulting silting was so heavy that after the Yellow River changed back to its northerly course for the most recent time in 1897, the geography of the Huai River basin was changed significantly by the creation of new high lands, lakes, and the built-up silt of the Yellow River's historical southern course. As a result, water from the midsection of the river could not easily flow into the lower section, while water in the lower section could not find an outlet to the sea. The problem worsened in the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...
, when the
Nationalist government, in an attempt to check the pace of the
Japanese invasion, flooded the lower Huai basin by opening the Yellow River's southern levee. The main stem of the Yellow River flowed through the levee breach for the next nine years, further disrupting the Huai river system.
The result of these changes was that water from the Huai River pooled up into
Lake Hongze, and then ran southwards towards the Yangtze River. Major and minor floods occurred frequently, with the area suffering droughts in between floods. In the 450 years to 1950, the Huai River saw, on average, 94 major floods per century.
Attempts to solve the Huai River's problems have focused on building outlets for the Huai River into the Yangtze River and the sea. Currently, the major part of the river's flow enters the Yangtze River via Lake Hongze. The
North Jiangsu Main Irrigation Canal also diverts some of its water along its old historical course to the sea, and is planned to be upgraded with a new parallel channel. Several former tributaries also carry some water to the sea.
Tributaries
There are many tributaries of the Huai River. There are 15 main tributaries cover an area of more than each, and 21 main tributaries have a catchment area larger than .
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The main tributaries on the Huai river (listed from upstream to downstream) are as follows:
References
External links
Huai River
{{Authority control
Rivers of Jiangsu
Rivers of Henan
Rivers of Anhui
Tributaries of the Yangtze River