Comprehensive evaluation on water environmental carrying capacity of Qiantang River watershed based on index system

Water environmental carrying capacity was related to economy,society,resource, environment, technology and management. Three indicators and fifteen variables were selected as the evaluation index, the three indicators including sustainable capacity of resource, assimilative capacity of environment and optimal allocation capacity of social economy. A comprehensive evaluation model of water environmental carrying capacity of Qiantang River watershed was developed. On the basis of the model, the current situation of water environmental carrying capacity was evaluated and different scenarios of recent or medium period were analyzed. The result of current situation evaluation showed that the water environmental carrying capacity of three regions decreased in the following order: Hangzhou>; Jinhua>;Quzhou, except 2001. In 2001, the order was Hangzhou >; Quzhou >; Jinhua. The different scenarios analysis indicated that all of the four kinds measure, such as maintain current situation, save water, increase investment of environmental protection, reduce amount of COD per unit discharge, could improve the water environmental carrying capacity of Qiantang River watershed in 2012 and 2015 respectively to different extents.