Discuss how natural geographical factors affect urban spatial distribution. Mainly from four aspects: rivers, topography, climate and vegetation.

In the plain areas in the middle and lower reaches of rivers, cities are relatively dense, because rivers can provide cities with a lot of water resources and convenient shipping. Flat areas are densely populated, and flat terrain is conducive to good traffic lines and urban infrastructure construction. Areas with moderate temperature and precipitation are densely populated and cities are densely populated. Areas with superior natural environment are densely populated with cities. There are fewer cities in arid areas with sparse vegetation.