Yan River

The Yan River () is a river in Shaanxi, China. The river flows from its source, the Xingzi River () in Jingbian County, in the prefecture-level city Yulin,^[1] and then flows through neighboring Yan'an,^[2] finally flowing into the larger Yellow River in Yanchang County, Yan'an.^[3] The Yan River flows a total length of 286.9 kilometres (178.3 mi), and has a total basin area of 7,725 square kilometres (2,983 sq mi).^[4]

Geography

The Yan River's source is Zhou Mountain (), in the town of Tianciwan Jingbian County, Yulin.^[1][4] The river then flows to the south into Yan'an, entering by passing through Ansai District.^[5]

The Yan River continues its flow south to Baota District,^[6] the urban center of Yan'an. In Baota District, the river passes through Hezhuangping, Qiaogou Subdistrict, Chuankou, Liqu, Yaodian, and finally, Ganguyi.^[4] The portion of the river which flows through Baota District totals 62 kilometres (39 mi), and has a basin area of 2,203.68 square kilometres (850.85 sq mi).^[4]

From Baota District, the river flows east through Yanchang County, where it merges into the larger Yellow River.^[3]

Characteristics

The Yan River is highly seasonal, due to the large disparities in the region's wet season and dry season.^[4] There is little year-round water flow contributing to the river.^[4]

The Yan River's basin follows a gradient of higher elevations in the northwest, and lower elevations in the southeast, resulting in the river's flow in that direction.^[4] Due to the geology of the Loess Plateau, the Yan River often follows a highly curvy path, and has a high sand content.^[4] Landslides are common in the Yan River's basin.^[4] 34% of the basin is covered in forest.^[4]

The normal flow of the Yan River is about 4 cubic metres (140 cu ft) per second, and the annual average runoff is 220,000,000 cubic metres (290,000,000 cu yd).^[4] The average sediment transport volume is 16 million tons.^[4]

History

Throughout China's long history, the Yan River has been called a number of different names. During the Warring States period, the river was known as the Qushui ().^[4] Later, during the Western Han, the river was called the Weishui ().^[4] Afterwards, in the Northern and Southern dynasties, and during the Western Wei, the river was known as the Qingshui ().^[4] During various points after the Western Wei, the river was called a number of other names, including the Jinshui () and the Zhuojinshui ().^[4] The current name, the Yan River (), is only a more recent name for the river.^[4]

Tributaries

The total length of the Yan River's tributaries total 10 kilometres (6.2 mi), and 11 of them have a basin area of over 100 square kilometres (39 sq mi).^[4]

Tributaries along the Yan River's left bank include the Fengfu River (), the Panlong River (), and the Wuyang River ().^[4] Tributaries along the river's right bank include the Xi River (), the Nan River (), and the Masi River ().^[4]

References

1. ^ "zh:靖边县概况地图" [Jingbian County Overview] (in Chinese). xzqh.org. 2015-04-13. Archived 2020-08-14 at the Wayback Machine. Retrieved 2021-09-19.
2. ^ "zh:延安市概况地图" [Yan'an Overview] (in Chinese). xzqh.org. 2016-07-15. Archived 2021-05-14 at the Wayback Machine. Retrieved 2021-09-19.
3. ^ "zh:延长县概况地图" [Yanchang County Overview] (in Chinese). xzqh.org. 2015-06-30. Archived 2020-01-19 at the Wayback Machine. Retrieved 2021-09-19.
4. ^ "zh:延安市志（地理志，第四章 水资源，第一节 地表水）" [Yan'an City Records, Geography Record, Chapter Four Water Resources, Segment One Water Surface] (in Chinese). dfz.shaanxi.gov.cn. Shaanxi Provincial Local History Office. 1994-12-01. Archived 2021-09-20 at the Wayback Machine. Retrieved 2021-09-19.
5. ^ "zh:安塞区概况地图" [Ansai District Overview] (in Chinese). xzqh.org. 2016-07-15. Archived 2021-06-07 at the Wayback Machine. Retrieved 2021-09-19.
6. ^ "zh:宝塔区概况地图" [Baota District Overview] (in Chinese). xzqh.org. 2015-06-30. Archived 2021-01-08 at the Wayback Machine. Retrieved 2021-09-19.