The date offers a striking temporal link to the Xia dynasty which, if it existed, is thought to have begun at this time. A modern Chinese chronology project sets the beginning of the dynasty at 2070 B.C. Even closer, two scholars working from Chinese astronomical records — a statement that there was a close conjunction of five planets early in the reign of the Emperor Yu — have calculated that the dynasty began in 1914 B.C.

Chinese annals record that Emperor Yu contrived a recovery from the Great Flood by dredging drainage canals rather than trying to repair breaches in the Yellow River’s dikes, as his predecessor had done. He also laid the foundations for the Chinese civilization that followed by specifying which regions should send tribute. The place where he began his operations is recorded as Jishi, which has the same Chinese characters as that of the gorge where the landslide dam occurred.

Dr. Wu’s team said its reconstruction of the outburst flood from the Jishi Gorge showed that the ancient textual accounts of the Great Flood “may well be rooted in a historic natural event.” The finding also supports the idea, the researchers say, that archaeological remains found at Erlitou, a site about 1,550 miles downstream from the gorge, may have been the Xia capital, given that the Erlitou culture dates to 1900 B.C., the same time as the Jishi Gorge flood.