Northeast China Plain

The Northeast China Plain or Northeast Plain (simplified Chinese: 东北平原; traditional Chinese: 東北平原; pinyin: Dōngběi Píngyuán), also known as the Manchurian Plain or Songliao Plain, is a lowland plain in Northeast Asia located in a vast, elongated basin formed by the Greater Khingan, Lesser Khingan and the Changbai mountain ranges, and forms the main portion of Northeast China (Inner Manchuria or "Inner Northeast"). Covering approximately 350,000 km2 (140,000 sq mi), the Northeast Plain is China's largest plain.

Geography

The Northeast Plain is bounded in the west by the Greater Khingan Range and northern/eastern branches of the Yan Mountains, in the northeast by the Lesser Khingan Range (which separates it from the Zeya–Bureya plains in the Russian Amur Oblast), in the east/southeast by branches of Changbai Mountains (e.g. the Zhangguangcai Range and Qian Mountains, which separates it from the Sanjiang Plain to the northeast) and in the south by the Liaodong Bay of the Bohai Sea. It has a mostly flat topography with an average elevation lower than 200 m (660 ft), and less than 100 m (330 ft) in the southern coastal regions.

The Northeast Plain consists of two primary alluvial plains, namely the Songnen Plain in the north, formed by the catchments of the Songhua River and its main tributary Nen River; and Liaohe Plain in the south, formed by the catchments of the Liao River and its former tributaries Hun and Taizi River. The watershed between the two plains is located among a series of low hills between Tongyu and Gongzhuling in central Jilin province. The alluvial soils of the Songnen and Liaohe Plains contain a large proportion of humus, making it the third-largest chernozem (black soil) region in the world after the East European Plain and the Great Plains. The excellent soil fertility, enhanced by the annual monsoon and snowmelt, is great for agricultural productivity and makes the region one of the most important breadbaskets in China nicknamed the "Great Northern Granary" (Chinese: 北大仓; pinyin: Běi Dà Cāng). The vast, fertile flatlands make the region suitable for large-scale human settlements, especially after the mass migration during the late 19th century.