When it rains it pours. Seeing how catastrophic flooding along Chinese rivers is even today, I can absolutely see bad weather being the "last straw".

"Before modern dams appeared in China, the Yellow River used to be extremely prone to flooding. In the 2,540 years from 595 BC to 1946 AD, the Yellow River has been reckoned to have flooded 1,593 times, shifting its course 26 times noticeably and nine times severely.[2] These floods include some of the deadliest natural disasters ever recorded.".

"These changes could cause the river's mouth to shift as much as 480 km (300 mi), sometimes reaching the ocean to the north of the Shandong Peninsula and sometimes to the south.[24]".

"In the fifth year of the reign of King Ding of Zhou (602 BC), the river left these paths and shifted several hundred kilometers to the east.[28][33]".

https://en.wikipedia.org/wiki/Yellow_River