A New Method for Regional Water Environmental Capacity Estimation Based on Natural-Social Water Cycle Analysis

Human´s social-economic activities have significantly interrupted the natural water cycle, particularly in urban area. The so-called binary natural-social water cycle issue has highly increased the complexity of urban water system. Traditional method to calculate water environmental capacity (WEC) depending on water quality model and long time series of monitoring data is sometimes not practical, especially at the planning stage or for strategy evaluation. Considering the influences of social-economic activities on natural water cycle, a new method for estimating WEC was developed in this study, focusing on diluting and mixing process of the water body. And then case study has been carried out in two cities located in northern China. Estimation of WEC and evaluation of carrying situation have been conducted, while the results are verified with monitoring data. It is indicated that the new method can be used as a practical tool supporting water environmental management in China.