Abstract: Green water resources indicate that the precipitation infiltrates into the soil unsaturated layer and returns to atmosphere by the plant transpiration and soil evaporation through hydrologic cycle, which is an important basis for the production of agricultural crops, however, it is usually ignored by traditional water resources management in the river basin. Based on the basin-wide water balance and concept of blue and green water，this paper proposes a method of taking green water resources into the basin water resources management. In the framework of the green water credit concept and game theory analysis, SWAT distributed hydrological model in combination with the multi-objective optimization and scenario comparison analysis, optimizes the allocation of watershed blue and green resources and coordinate interest conflicts between upstream and downstream through green water management and green water compensation. Accordingly, the game theory framework of basin green water management is exploratory proposed. This method can identify and analyze game space, game structure and Nash equilibrium of basin green water management by game modeling and can calculate green water compensation standards and Pareto optimal in different green water management scenarios by the improved optimization method and its cooperative game theory constraint conditions. Moreover, the game theory framework of green water management has been applied to the Lianshui river basin, and the simulation and uncertainty analysis results of NSE, R2, PBIAS, p-factor as well as r-factor indicated good performance of blue and green water simulation for the constructed SWAT distributed hydrology model in the Lianshui river basin. The game analysis results of revenue change between upstream and downstream, green water compensation standard and Pareto optimal solution set show that the overall socio-economic and ecological benefits of the Lianshui basin improved significantly. Its Pareto-optimal income increased by an average of 272 million yuan/a, and the average annual green water compensation standard was 1.94 yuan/m³ and 1 253.7 yuan/hm², which proved good applicability and feasibility of the proposed game theory framework of green water management in the Lianshui river basin. Consequently, this method can provide relevant theoretical basis and technical reference for the future river basin pilot study of blue and green water management and its green water compensation standard estimation, which has a certain degree of application value and practical significance.

Key words: blue water, green water, SWAT, game theory, green water credits, eco-compensation, Lianshui basin