Flood was a foundational myth of Chinese culture concerning a major flood said to have lasted at least two generations amid storms and famines. Chinese legend traditionally places it during the third millennium BCE reign of the Emperor Yao. The River Map typically plays an important role in Yu the Great's eventual successful control over the flooding waters c. 2200–2100 BCE. He Bo The personification or deity of the Yellow River holds the rank of count or earl (bo) in the celestial bureaucracy and is accordingly known as He Bo. In some accounts, he is involved in providing the River Map. Houtu Houtu () is a male, female, or non-gendered divinity depending on the source, although the image of a Sacred Mother Earth deity is now common. Houtu is worshiped in Chinese popular religion, with her birthday on the 18 day of the third month of the Chinese lunar calendar. Sacrifice and prayer to Houtu are believed to be efficacious for problems of weather, reproduction and family, wealth, and boating safety on the Yellow River. According to one account, when Yu the Great was attempting to channel the Yellow River and so avoid its flooding, he began by trying to open it to the west towards the mountains and away from the sea. Observing this, Houtu is said to have created and studied the River Map, after which she sent divine messenger birds to Yu to tell him to open up the river to the east instead. Yu's new dredging was a success, the flood waters drained into the eastern sea, and Yu's former dredging project toward the west was named the "River Wrongly Opened". In this story, Houtu and the River Map were key to the successful engineering solution to the flood problem. Historical evidence The River Map is attested to in the Gu Ming section of the Book of Documents, one of its "new text" sections. Supposedly, the River Map was put on display during the Zhou dynasty. However, this has also been interpreted to mean a depiction of the 8 trigrams (bagua). This incident is recorded to have been during the reign of the Zhou Kangwang, who reigned either about 1020–996 BCE or 1005–978 BCE. Literature The I Ching cites the River Map and the Luoshu. Interpretation Interpretation One way of analyzing the Yellow River Map is by comparison with the Luoshu. Wolfram Eberhard says that the