The survival of the societies of the orient are interesting and not completely understood even today.

The history of Asia is mired in cultural revolution.  As time went by the ancients became a road map of the future of the Chinese communists.  Their ancients are not necessarily correctly interpreted, so much as 'decided' by power that be, rather than scientific standards.

The Chinese origins began along the river system.  The ancient river systems of The Yellow River and the Yangtze and their tributaries.

The interesting aspect to the ancient Chinese civilizations is the realization they lived along rivers and were destroyed by them due to the low elevation and episodic flooding due to ice ages and their warming.

Some of the very earliest Chinese civilizations were literally drowned when ice caps melted and covered the land creating oceans.

See, some of the ancient pollens found in China didn't originate there.  While further study is necessary, the pollens indicate a far different origin.

What occured during ice ages, of which caused four of the past five extinctions on Earth, is that massive amounts of water (fresh water) were frozen in the caps of Earth.  This exposed the entire coastal plain off of the Yangtze and Yellow Rivers.  There was a time when the Yangtze River had a mouth that reached into the coastal area now covered by the Pacific Oeean waters.  When that occured and the coastal area of China was exposed the plants were not developed.  Their pollens were airborn and little were water born as the headwaters of the great rivers were serviced as much from melting 'edge' glaciers as any other source.  There were no plants growing on the glaciers and today the best any glaciologist can find anywhere are lichens.

So, the pollen that is found in ancient sediments at the old mouth of the Yangtze belongs to ancient plants of Japan.  The other possibilities are too remote to have an influence.

So, as the ice caps melted and the waters increased in the oceans the coastal plain of China began to flood.  For unsophisticated societies and villages there was no understanding to know how to survive.  Many coastal villages of these ancients drowned, but, the survivors moved further inland and up the river systems. 

The flooding would cause changes in course of the grand rivers of ancient China.  This too would bewilder the people and cause their deaths and diminished numbers.

Some of the cultures would survive, but, some would not.  The Quinliangliang culture is one that would be lost and its remains incorporated into 'the tales' of other Chinese societies.

Today, the Quinliangliang culture is nearly considered a myth.

Over time the Chinese cultures would become a mystery to other civilzations as they were fierce warriors with ancient medicinal methodologies.  Very spiritual.  The kings and rulers were not gods, but, treated with enormous dignity and as if a treasure.  They were the 'schooled' people that would come to understand survival and now best to maintain their people. 

The ancient Mongolians would have a genetic influence on the Russians of the north.  The ties between Russia and China exceed their common governmental systems, but, reach back millenium.  That is something the juvenile cultures of the Americas simply don't understand and choose not to.