『Abstract
　With overly-rapid socio-economic development and population increases, water abstraction for agricultural, industrial and municipal use increases rapidly, while the water left for ecological maintenance decreases greatly. At the same time, large amounts of polluted water are discharged into rivers because purification plants are inadequate or not built in time, causing serious eco-environmental problems in the Haihe river basins which make regional development unsustainable. Estimating eco-environmental carrying capacity related to water is a key to curbing overuse of water and resolving eco-environmental problems. Because of different trends in water resources development and resultant eco-environmental problems in different sub-basins of the Haihe river, there are different water-related eco-environmental carrying capacities (EECCs) in these sub-basins. Time-series and multi-objective optimization methods are used to determine the EECC in various eco-environmental regions of the Haihe river basins, China. The results show that the entirely of the Haihe river basins will not reach a stable, sustainable state until about 2033, through gradual amelioration of eco-environmental problems. The various eco-regions of the sub-basins will need different lengths of time to reach their own stable states because of different available water resources, eco-environmental problems and social and economic development.

Keywords: Multi-objective optimization method; Time-series; EECC; Haihe river basins』

1. Introduction
2. Materials and methods
　2.1. General situation of the Haihe river basins
　2.2. Calculation of eco-environmental carrying capacity
　　2.2.1. Model description
　　　Objective functions
　　　Constraints
　　2.2.2. Analysis of maximum eco-environmental loading
　　2.2.3. Calculation scheme and material source
　　2.2.4. Calculation process of the carrying capacity
　　2.2.5. Results of carrying capacity calculation
3. Results and analysis of their rationality
4. Conclusions
Acknowledgements
References