Optimizing water rights allocation for the Hebei section of China’s South-to-North Water Diversion Middle Route Project using asymmetric game theory

Reasonable and efficient inter-basin water resources utilization is critical in alleviating water supply-demand constraints in water-scarce regions, improving rivers and lakes ecological conditions, and promoting high-quality socio-economic development. The current water rights allocation scheme for the Hebei section of the South-to-North Water Diversion Middle Route Project does not match the current and future water demand of the targeted regions. This study proposes a two-stage water rights allocation method by developing area-specific negotiated scheme and constructing a water rights allocation model based on the asymmetric Nash-Harsanyi negotiation solution model-to optimize the water rights allocation scheme for the Hebei section Project areas for 2030. The results indicated 4.207 billion m³ as the total water rights allocation for the water-receiving areas, with 2.525 billion m³ allocated for basic water demand. Compared with the current scheme, the optimized water rights allocation for Langfang City and Xiong'an New Area increased to 3.53 × 10⁸ m³ and 2.10 × 10⁸ m³, respectively, which further supports the construction of Xiong'an New Area and the coordinated development strategy of Beijing's Tongzhou District and Langfang's northern three counties. The proposed model balances the fairness and efficiency of water rights allocation while ensuring the basic water demand of the water-receiving areas.