What is the Mandate of Heaven? Based on this belief,
how might the flooding of the
Huang He have affected the
rule of a Zhou king?

The Mandate of Heaven is a Chinese political philosophy that was used in ancient and imperial China to justify the rule of the King or Emperor of China. According to this doctrine, heaven – which embodies the natural order and will of the universe – bestows the mandate on a just ruler of China, the "Son of Heaven"

The Yellow River in Ancient China

Unified behind strong leaders and able to produce bountiful harvests since Yellow River floods no longer destroyed their crops so often, the Xia Kingdom ruled central China for several centuries. ... He was almost as powerful an influence on Chinese culture as the river itself.

it's a secular holiday. it is and was a custom developed to recognize the ending of a time and a wish for a good future. the kind of kiss you exchange, if you are single, is intended to predict what kind of year you will have in the coming year.

it is saying good bye to the last year with all its ups and downs, and hello to the new year, with all its hopes and dreams.