Spatial optimization of cotton cultivation in Xinjiang: A climate change perspective

Global climate change is shifting the temperate climate zone towards higher latitudes, altering crop adaptability and potentially impacting cotton (Gossypium hirsutum L.) cultivation's climate suitability distribution. However, our understanding of these impacts is often based on one-sided suitability assessments, leading to potential biases when optimizing cotton planting spatial distribution and adaptability. In this study, we utilized a cotton cultivation spatial optimization framework, combining Geographical Information System (GIS) and Remote Sensing (RS) techniques, to accurately identify locations with ongoing land-use disputes. We then analyzed the extent of discrepancy between cotton suitability and planting zones under the influence of climate change. The results demonstrate the stability of suitable cotton cultivation areas in the southern (19%), northern (4%), and eastern (1%) regions, indicating a comparative advantage in climatic resources for the southern region. The climate-suitable areas for cotton were mainly concentrated on the south side of the Tianshan Mountains and near the Tarim River, covering the regions of Aksu, Hetian, Kashgar, and Bazhou. However, with the notable increase in effective accumulated temperature, precipitation, sunshine hours, and minimum temperature, the proportion of very highly suitable and unsuitable areas decreased, while the proportion of less suitable areas increased. Additionally, climate change led to the expansion of cotton suitable areas towards North Xinjiang. Moreover, the cotton cultivation center shifted from South Xinjiang to North Xinjiang during 2000–2020 and then returned to South Xinjiang, with the cotton cultivation areas in South and North Xinjiang being nearly balanced by 2021 (49% each). Despite a decrease in the conflict rate between cotton cultivation zones and suitable areas from 60% to 33% during 2000–2020, the conflict rate remained relatively high. It is reasonable to attribute this discrepancy to the significant influence of the target price policy and agricultural technological advancement in both South and North Xinjiang. Overall, our study effectively identifies land-use conflicts and suggests optimizing the spatial layout of cotton planting in Xinjiang. This can leverage agricultural resource advantages, reduce production costs, and provide valuable policy references for the decision makers.