which associate the rise of the first dynasty with King Yu’s successful dredging work after the inundation, say it began at a place called Jishi, the name of the gorge where scientists think the historical flood began. While the evidence awaits full publication, what we can say for now is that a series of ecological crises between 2300 and 1900 BCE, including perhaps a great Yellow River flood, appear to coincide with dramatic political changes in the central plain.
