Evaluation of water resources carrying capacity in Ordos city based on the Game Theory-Topsis-Grey Prediction coupling model

Under the national strategy of ecological protection and high-quality development in the Yellow River Basin, Ordos, a major coal production base in China contributing ~ 17.1% of China’s annual raw coal output, faces prominent water shortage and ecological fragility. This study constructed a “Game Theory-TOPSIS-Grey Prediction” coupled model: it integrated subjective and objective weights via game theory (reducing weight coefficient of variation by 35%), evaluated water resources carrying capacity (WRCC) during 2000–2023 (the WRCC index increased from 0.3285 to 0.6373, with an average annual growth rate of 2.92%; growth slowed to 1.69% during 2016–2023, showing a “strong east-weak west” spatial pattern), and predicted WRCC trends for 2025–2040 using the GM(1,1) model. The GM(1,1) model achieved first-level accuracy (average relative error 6.35%, posterior error ratio 0.327, small error probability 0.962), with predicted WRCC indices of 0.6261 (2025), 0.7676 (2030), and 0.9736 (2040). This study provides a dynamic tool for “water-energy-ecology” coordinated governance of resource-based cities in China’s Yellow River Basin.