Changes of Zhanghe River.

Zhanghe River was originally the largest tributary of the middle and lower reaches of the Yellow River. Gong Yu's reference to Zhangheng and precipitation is Zhanghe. Later, the Yellow River moved south, and Zhanghe left the Yellow River and merged into the Haihe River system, becoming a major tributary of the Haihe River. Historically, its changes are more complicated. Its changes can reach Anyang River in the south, Fuyang River in the north and its predecessors Hengshui, Luchang or Hulu River, and its peak is in the west of Ye Zhen (ancient Yedu), namely Santaikou. In ancient times, there were two tributaries in the lower reaches of the Zhanghe River. Since Cao Cao dug the Cao Li Canal, there has been a south branch supporting the canal, and the Zhanghe River is divided into three branches. Since Sui and Tang Dynasties, Zhangshui has become unstable. During the Ming and Qing Dynasties, in order to support water transport, the lower reaches of the canal diverted water from the Zhanghe River, ranging from three branches to 1 branch, which made the changes of the Zhanghe River more frequent and complicated. After Kangxi in the Qing Dynasty, the Zhanghe River was completely owned by the canal from this Guantao, forming today's Zhanghe River.

The Zhanghe River above Yuecheng Reservoir runs through the Taihang Mountains with an average longitudinal slope of 1/260. The current is swift and fierce, and the rapids go straight down the canyon and over the cliff. "Zhang Shui Hong Tao smells for miles" (Ji Fuan Lan Zhi). Floods carry a lot of sediment. According to the statistical analysis of data from 1923 to 1965, the average sediment discharge of Zhanghe Observatory for many years is 25.8 million tons. "Although the turbid water in Zhanghe River is yellow, it is easy to accumulate yellow", so Zhanghe River is known as the "Little Yellow River". In Haihe River basin, the sediment transport capacity of Zhanghe River is second only to Yongding River.

The ancient Zhanghe River changed many times because of the influence of the Yellow River. The Yellow River has been diverted from Tianjin to the sea twice in history. The first time was from the fifth year of King Ding Zhou (602 BC) to the third year of the founding of the People's Republic of China (A.D. 1 1 year); The second time was from the eighth year of Song Liqing (AD 1048) to the fifth year of Jin Zhangzong Mingchang (AD 1 194). Twice * * * 759. The Yellow River has the characteristics of high flood peak, high sediment concentration, good siltation and good migration. When it meets a river, it will be caught. Not only the Weihe River and the Zhanghe River are difficult to cross, but the Hutuo River, which originally entered the sea alone, has to change its direction. Along the Yellow River, the northeast flows from Tianjin to the sea. The Yellow River is the main reason for the formation of Haihe River system.

In the Jin Dynasty, after the Yellow River seized the Huai River and entered the sea, it left the old course of the Yellow River on the ground of North China Plain. Coupled with the high sediment concentration in the Zhanghe River, the lake has been turned into a flat land, the river has risen, and the discharge has been blocked, so that the Zhanghe River often overflows and cannot be controlled. During the 242 years from the ninth year of Shunzhi in Qing Dynasty (A.D. 1652) to the twentieth year of Guangxu (A.D. 1894), the Zhanghe River flooded 40 times, with an average of 6 years 1 time. People call it "the unruly Zhanghe River". According to the Records of Linzhang County, "In July of the forty-third year of Jiajing in Ming Dynasty (AD 1564), (Zhanghe) dyed the west gate of Zhoucheng; In the sixth year of the Apocalypse (A.D. 1626), water reached the gate. In the third year of Chongzhen (AD 1630), Xia Dingnan Emperor was normal in his later years. " According to the Records of Yuancheng (Daming) County, "In the thirty-sixth year of Jiajing (A.D. 1557), Zhang and Wei were scattered in Daming, Nanle, Wei, Qing and Neihuang counties, and people lived in nests."

There are roughly three distributary paths in the history of Zhanghe River. One is the confluence of Zhangbei River and Fuyang River, which is called North Road in history. Generally, it starts from Linzhang, passes through Guangping, reaches Qiu County, leaves the northwest of Wei County and crosses Xinhe County. Secondly, the southbound Zhanghe River meets the Weihe River, which is called South Road in history, so the old road generally goes from Linzhang, wei county and Jingming to Guantao, and then goes up to Guantao. The third is the middle road between North Road and South Road, starting from Linzhang, passing through Feixiang and Guangping to the northeast, reaching the junction of Jixian and Hutuo River, and then flowing northward through Hejian and other places to Tianjin to enter the sea. In terms of time, it takes the longest time to go south. From 575 in A.D. 1368 to A.D. 1942, it took 347 years to go south.

The south road into the Weihe River has also undergone several changes. Ming entered Wei in Feixiang in 13, and entered Wei in Yanjia, daming county in the early Ming Dynasty; Ming Jiajing entered huilong town again; Soon, he joined the guard in Shi Cun, Neihuang County. In the forty-seventh year of Emperor Kangxi of Qing Dynasty, Zhang entered Wei and went south. Since then, although the Zhanghe River has changed, it has been in the South Road. From 1942, Zhanghe entered Xuwan Cangwei, Guantao County, Hebei Province, and now Zhanghe and Weihe River have merged.