An empirical analysis of the impact of the coupling coordination degree of the water-energy-food nexus on food security in China

Food security has been challenging in many countries due to climate change, population growth, water scarcity, and bio-energy development. This work quantifies the impact of water-energy-food (WEF) nexus coupling coordination on food security in China through a multidimensional approach to promote food security and resource sustainability. We first quantify the coupling coordination degree of the WEF nexus using the entropy weight TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method. And then Ordinary Least Squares Multiple Linear Regression model is employed to explore the impact of the WEF nexus coupling coordination degree on food security. The findings show that an improvement of 1% in the coupling coordination degree of the WEF increases the total grain yield, per capita grain yield, grain yield per unit by 2.69%, 1.12% and 2.77%, respectively. It is also found that improvement of WEF coupling coordination is conducive to enhancing food self-sufficiency rate and stabilizing food price. And the increment in grain yield is achieved by increasing the effective irrigated area and agricultural machinery inputs. Furthermore, the heterogeneity analysis reveals that the effect of the WEF nexus on the total grain yield and per capita yield is more significant in the central region, and the improvement of grain yield per unit is more effective in the west. Meanwhile, the interaction term analysis demonstrates that cropping structure, agricultural subsidies, and water-saving technologies all strengthen the positive contribution of the WEF nexus to food security.