Impact of spatial transfer of farmland on the food-water-GHG nexus in China during 2000–2020

Analyzing the impact of spatial transfer of farmland (STF) on the food-water-greenhouse gases (FWG) nexus through a coupled perspective holds significant scientific value for guiding sustainable farmland management policies. This study developed an integrated assessment framework to quantify FWG-nexus dynamics induced by STF, systematically evaluating changes in crop yields, irrigation water consumption, and GHG emissions across China from 2000 to 2020. The coupling coordination degree (CCD) of the FWG system was further examined. The results show that between 2000 and 2020, the area of farmland in China decreased by 2.63 × 10⁴km², and the center of gravity of farmland shifted approximately 56.90 km towards the northwest. Nationwide, STF led to an increase in average crop yields by 58.54 kg/ha; at the same time, the average irrigation water consumption increased by 1.93 mm, and the average GHG emissions also rose by 23.63 kgCO₂-eq/ha. During the study period, the FWG-nexus exhibited a tendency toward decoupling, as indicated by a 0.21 % decrease in the FWG CCD. The increasing consumption for irrigation water and rising GHG emissions have consistently been the primary constraints to the harmonization of the FWG-nexus at the national level, with notable regional variations of these constraints. These insights help deepen the understanding of the impact of STF on the FWG-nexus, providing scientific support for sustainable land use in China and the achievement of the United Nations Sustainable Development Goals (SDGs).