Assessing the Environmental Impact of Oasis Agriculture in the Yarkant River Basin: A Comprehensive Study of Water Use, Carbon Footprint, and Decoupling Index

Studying the relationship between grain planting and the environment is an important means to promote sustainable production. This study takes wheat, a typical grain crop in the Yarkant River oasis irrigation district, the fourth largest agricultural irrigation district in China, as an example to analyze the relationship and changing trends between wheat yield and water footprint (WF), and carbon footprint (CF) from 2001 to 2020. The study found that during the research period, wheat yield, WFgreen,blue,WFgrey, and CF showed a fluctuating but significantly upward trend. Decoupling analysis indicates that the overall decoupling trend between wheat yield and water footprint and carbon footprint is not obvious. This suggests that the rapid development of wheat production in the Yarkant River Oasis has also led to significant water resource consumption, pollution, and greenhouse gas emissions. Among the three sub–irrigation districts, the Shache sub–irrigation district has the best decoupling state, reflecting that the increase in wheat yield in Shache did not lead to more water resource consumption and pollution which is may due to its abundant water resources and agriculture development. Further analysis found that the use of nitrogen fertilizers and irrigation electricity have contributed to water resource pressure and greenhouse gas emissions. This study reveals that there are significant environmental risks in the current wheat planting in the Yarkant River oasis irrigation district, but it also points out the direction for green development in the irrigation district.