Temporal-spatial evolution and coupling analysis of water-energy-carbon nexus for crop production: A case study of Sichuan Province, China

Water, energy, and carbon are crucial factors that influence crop production efficiency. A comprehensive understanding of their intricate relationships is essential for achieving sustainable and coordinated development of regional agriculture. Quantifying these interrelationships is significant for addressing resource scarcity and climate change. However, current research on the water-energy-carbon nexus agricultural production primarily focused on national and strategic regional levels, with limited studies on specific regions. In this study, we assessed water consumption, energy utilization, and carbon emissions using footprint theory, analyzed their spatio-temporal evolution trends and spatial agglomeration characteristics through standard deviation ellipse analysis and spatial autocorrelation analysis, and evaluated the level of coordinated development among them through the coupling coordination degree model in Sichuan Province from 2011 to 2021. The results indicated that annual water consumption was 6.25 × 10¹⁰m³, energy inputs and outputs were 4.07 × 10¹⁰MJ and 6.71 × 10¹¹MJ, while carbon emissions and sinks were 3.35 × 10¹⁰kg and 1.31 × 10¹¹kg in agricultural production. The spatial density of the water footprint, energy input, and carbon emissions exhibited decreasing trends, suggesting a continuous weakening of their agglomeration effects. The global autocorrelation analysis were not significant. The HH clusters for water footprint, energy input, and carbon emissions were mainly found in the northeast Sichuan region. The coupling degree of the water-energy-carbon nexus showed good performance, with the coupling coordination degree ranging between 0.3 and 0.5. Therefore, it is necessary to implement measures to reduce water and energy consumption as well as carbon emissions, such as adopting integrated water and fertilizer management, partially replacing chemical fertilizers with organic manure, and promoting no-till and minimum-till farming practices. This study provides valuable insights for coordinated management and sustainable development in agriculture.