In the last millennium Yellow River breached its dikes
near the ancient city Kaifeng (once the capital of
the Song dynasty, c 11th century) 64 times.
The city was inundated by floods 8 times.
In a recent archaeological excavation it was found that
the city had been raised 9 m by sediments deposited from floods.
The top picture shows the thick layer of deposit
over which the modern city rests. Dikes had been
constructed along the river for over 3 millennia.
The bottom picture shows the remnant of a dike section
built during the Han dynasty (c. 100 B.C.).
Picture source: YRCC, Huanghe Feng,
Yellow River Pub House, 1996.