Calculation methods of water environmental capacity of surface waters：Review and prospect

The study aims to clarify the evolution of calculation methods of water environmental capacity of surface waters in China, and to discuss the development trend. Based on the systematic reviewing of previous relevant studies, the research history of water environmental capacity from the introduction of concept to current studies and then five calculation methods of water environmental capacity of surface waters in China were summarized as follows: Formula method, trial-and-error method, system optimization method (linear programming method and stochastic programming method), probabilistic dilution model method, and unascertained mathematical method. The basic theories, formation, and applications of the five calculation methods are analyzed. The scope of application, merits and drawbacks of each method are also commented. Taking into account of many factors including research trend, complexity of environmental issues and the demand for water resources management in China, it is suggested that the research in China should be focused on the development of the three methods: Probabilistic dilution model method, stochastic programming method and unascertained mathematical method.