North China Plain

A large plain that occupies most of the eastern half of North China. It is also called the Huang-Huaihai Plain. It is the second largest plain in China, formed by the alluvial action of the Yellow River, the Huai River, and the Hai River, and covers an area of ​​approximately 310,000 square kilometers. The terrain is extremely flat, with most of the area below 50 meters above sea level. Apart from a large alluvial fan that has developed on the border with the Taihang Mountains in the west, the rest of the area is a lowland with an extremely gentle slope, and the coast of the Bohai Sea has undergone repeated marine transgressions and regressions. It became land due to the inflow of a huge amount of sediment from the Loess Plateau, but subsidence continues to this day. Most of the area was filled in by sediment discharged by the Yellow River, but as the Yellow River itself became an overhead river, the riverbed became the watershed of the Hai River to the north and the Huai River to the south, and the Yellow River is still forming a huge delta at its mouth. The plain is China's largest cotton-growing area, and there are large reserves of petroleum resources beneath the thick sedimentary layers underground, with oil fields in Shengli, Dagang, North China (Renqiu), Zhongyuan, and other areas being developed.

[Kono Michihiro]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

中国、華北地区東半の大部分を占める大平原。黄淮海(こうわいかい／ホワンホワイハイ)平原ともいう。黄河、淮河(わいが)、海河の沖積作用によって形成された中国第二の大平野で、面積約31万平方キロメートル。地勢はきわめて低平で、大部分は標高50メートル以下である。西の太行(たいこう)山脈との境に大規模な扇状地が発達するほかは、勾配(こうばい)のきわめて緩やかな低地をなし、渤海(ぼっかい)沿岸は海進・海退を繰り返した。黄土高原からの莫大(ばくだい)な量の土砂の流入により陸化したが、現在もなお沈降が続いている。大部分は黄河の流し出した土砂で埋積されたが、黄河自体の天井川化により、黄河河床を分水界として北は海河、南は淮河の流域となっており、黄河はいまも河口に巨大なデルタを形成中である。平原上は中国最大のワタ作地で、また地下の厚い堆積(たいせき)層の下部に大量の石油資源の埋蔵がみられ、勝利、大港、華北（任邱(じんきゅう)）、中原(ちゅうげん)などの油田が開発されている。

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