The Resource-Environment Performance Index and Drivers of Coarse Cereals in Shanxi Province, China: A Coupling Analysis of Water and Carbon Footprints

Abstract

Coarse cereals are indispensable to both national food security and the implementation of the Healthy China Initiative, underscoring the urgent need to promote their green and low-carbon production. Using panel data from Shanxi Province spanning 2010–2020, this study first employed water footprint (WF) and carbon footprint (CF) accounting methods, together with a coupling coordination degree (CCD) model, to characterize the spatio-temporal dynamics of WF, CF, and their CCD for six major coarse cereal crops across the province. On this basis, the entropy-weighted TOPSIS model was applied to assess the spatio-temporal patterns of the resource-environment performance index (REPI), while exploratory spatial data analysis (ESDA) was used to detect spatial autocorrelation. Subsequently, path analysis was conducted to identify the key determinants of REPI. The results indicated that: (1) both total WF and CF per unit yield exhibited declining trends with pronounced spatial heterogeneity, generally higher in northern Shanxi, relatively balanced in the central region, and lower in the south; (2) the CCD between WF and CF showed a sustained upward trajectory over the study period; (3) the REPI of all selected coarse cereal crops increased significantly; and (4) effective irrigated area exerted the strongest positive effect on REPI, whereas the mean minimum temperature, the net application rate of agricultural chemical fertilizers and the proportion of leguminous coarse cereals imposed notable negative effects. Accordingly, we propose the following targeted strategies: expanding water-saving effective irrigated areas steadily, strictly curbing fertilizer overuse, tailoring dominant coarse cereal varieties to local agro-ecological conditions, and optimizing the region-specific development of characteristic coarse cereals.