The order of the pollution for serious level to light level in the seven key river systems in 2001 is: Hai River, Liao River, Huai River, Huang River, Song Hua River, Yangtze River and Pearl River.

• 2001年度七大水系污染由重到轻的顺序依次是: 海河、辽河、淮河、黄河、松花江、长江和珠江。