How did geography affect life in ancient china?

As in any other country, geography shapes the history and the economy. Geography commands not only the climate, rivers mountains, but also religion and culture. 
China to begin with is among the largest countries in the world, and is the most populous. Most of its population is at the coast, because it has access to water and to ocean, thus can feed themselves better than people from the mountains. 
Inside the country, there are deserts and mountains, and ancient Chinese preferred those location to build monasteries and sacred places,and also used it as a protective shelters in times of war. 
Geography also affects what people's diet, their soil is good for rice, given the humidity, which cause the ancient Chinese to live on rice-paddies, in large families.Due to extensive labor it required to grow rice on the farm, Chinese had a lot of kids, which they try to prevent lately. So geography affected their social life, living in big families, with many children, embedded respect for elderly, and reinforced family ties. 
Another particularity, are Chinese rivers, The Yellow river, is lately drying out, but it is known to flood many provinces in ancient times, so people would grow certain flood resistant plants there, and also build cities, that can rely on waterway for their water supply and transportation.

Geography shapes the history and the economy. Geography controls what happens in a certain part of the world.

Wish I could help more.

Answer they are produced by collision of tectonic plates;