The Earth and its peoples chapters 3 and 4, edition 5
Subject:
Chapter 3: Geography and Resources China is isolated by formidable natural barriers including; Himalaya mountain range, Pamir and Tian Mountains, Takla Makan Desert, Gobi desert, and Mongolian steppe. Since most of east china is completely covered with mountains, its difficult to travel overland. The yangzi and yellow rivers (and their tributaries) allowed for east-west movement. Most people lived in the river valleys of the yellow river (Dense populations) but a few lived on the steppe lands of Mongolia by heading. The north and south have completely different environments, at first that meant the north (with erratic rainfall) had more innovation and technology for things like irrigation projects, but later it meant that people just moved to the south.
