The most important topographic feature of this region is the
loess plateau, which is badly eroded into thousands of deep
gullies and is the main source of sediment production for the
river. About 25% of the land is cultivable, and forest coverage
is about 11%. Nearly 77% of the basin's grasslands are found
in the upper reaches, 18% in the middle reaches, and only 4% in
the lower reaches. Its Wei River valley is accredited to be the
"cradle of Chinese civilization," and together with the Fen River
valley, they form the most thickly populated areas of the region.
The following list of sites are illustrated: