The impact of climate change and human activities on grain production efficiency in the Yangtze River Basin and its policy implications

Exploring the impact of climate change and human activities on grain production efficiency is of great significance for ensuring national food security and promoting regional sustainable development. This study takes 135 prefecture-level cities in the Yangtze River Basin (YRB) as research units and uses relevant data from 1990 to 2022. The Super Slack Based Measure (Super-SBM) model is applied to measure the level of grain production efficiency, and further analyses are conducted using the Geographically and Temporally Weighted Regression (GTWR) model and Pearson correlation method to systematically examine the impact effect of climate change and human activity factors. The results show that: (1) From 1990 to 2022, grain production efficiency in the YRB exhibited a slow upward trend, with the average level rising from 0.4659 to 0.5990. The spatial pattern displayed a southwest-to-northeast distribution, with high-efficiency areas gradually concentrating in regions such as Hubei and Sichuan. (2) The grain production efficiency in the YRB is significantly influenced by climate change and human activities, exhibiting pronounced spatiotemporal heterogeneity. (3) The impacts of climatic factors are predominantly positive, concentrated in the middle and lower reaches of the YRB, with the influence intensifying over time. Expansion of construction land and population agglomeration exert negative effects in the middle and lower reaches of the YRB, while showing positive impacts in certain upstream regions. Agricultural production intensity exhibits negative effects in the middle and upper reaches but positive effects in the lower reaches. Economic development exerts a negative influence across the entire basin, with relatively weak impacts in the middle and lower reaches. Accordingly, it is recommended to formulate region-specific, climate-adaptive agricultural development strategies, while optimizing patterns of human activity interventions, so as to promote high-quality and sustainable agricultural development in the YRB.