On Sustainable Evaluation of Water Resources in Yanhe River Basin Based on Water Footprint Theory

Based on the SWAT model and the water footprint theory, the blue and green water quantities in the Yanhe River Basin were simulated, and the sustainability of its water resources was evaluated. The results indicated that during 1980-2020, the average blue and green water quantities in the Yanhe River Basin were 4.568 billion m³ for many years, with the blue and green water coefficients being 30.6% and 69.4% respectively. The composition of water resources was dominated by green water. The policy of returning farmland to forest alleviated the water resources stress in the basin, with the water resources shortage index dropping from 0.40 to 0.36. The return of farmland to forest had a positive effect of alleviating the water resources pressure in the basin, reducing the water resources pressure index by an average of 33.89%. The multi-year average grey water footprint in the basin was 0.862 billion m³ for many years.