Water Environmental Capacity Calculation Based on Unascertained Information

Hydrologic system is an unascertained system. For design discharge calculation according to design criterion , different results are likely to be gained if using different methods or different samples . Design water environmental capacity of river reach also has unascertained characteristics. On the basis of unascertained characteristics of water environmental capacity, a new calculation method for water environmental capacity of river reach is put forward according to the theory of unascertained mathematics. The result shows that the method is efficient.