The calculation results of pollution contribute rate of 21 indexes of Liao River, Xiang River and their
mainstreams as well as tributaries are listed in Table 3. According to the data in the table, a huge
difference occurs among various indexes in one river and also one certain index in different water bodies
differs from each other. The pollution contribute rate of potassium permanganate index, COD, 5-BOD and
ammonia nitrogen all account for more than 10%, among them, more than 20% ammonia nitrogen
pollution contribute rate is all above 20%. The pollution contribute rate of fecal coli form in Liao River
and its mainstreams is more than 10%, however, that is less than 5% in Liao River’s tributaries. Fecal coli
form is the only one of which pollution contribute rate of Xiang River and its mainstreams as well as
tributaries is more than 10%, and its pollution contribute rate also amounts to as30% in Xiang River and
its mainstream, which is definitely more than that in the Liao River and its mainstreams as weill as
tributaries. It is also a great proof to verify that there is a huge difference between the characteristics of
water contamination in different water bodies.