Quantitative evaluation of variation and driving factors of the regional water footprint for cotton production in China

Water resources are the foundation that supports life and have become a key constraint on agricultural development in the 21st century. The water footprint (WF) provides a new and comprehensive approach for water utilization in agriculture, but WF of cotton in China has not been extensively studied. This study analyzed the spatiotemporal variation characteristics, driving factors of WF and evaluated the water resource utilization benefits and water stress caused by cotton production in China from 2004 to 2018. WF of cotton in China showed a decreasing trend, while the increase in unit yield was the main reason for the decrease in WF. The total water footprint (TWF) in the Huanghe Valley, Yangtze Valley and Northwest Inland cotton regions was 11G (46.6 % TWFgreen (total green water footprint), 42.0 % TWFblue (total blue water footprint), and 11.3 % TWFgrey (total grey water footprint)), 15G (37.0 % TWFgreen, 19.0 % TWFblue and 43.9 % TWFgrey), and 18G (9.9 % TWFgreen, 80.5 % TWFblue, and 9.6 % TWFgrey; 1G = 109 m3), respectively. Exploratory spatial clustering identified the Yangtze Valley cotton regions as a High-High clustered zone for WF, which indicated a high WF and low output. The pressure on water resources gradually decreased in the Huanghe Valley cotton region, and it was in a low WF and low output situation. In the low WF of high output of the Northwest Inland cotton regions, its Low-Low cluster had a tendency to shrink, and the water pressure showed an increasing trend. The results of this study provide new insights into reducing the consumption of water resources and promoting the sustainable production of cotton.(c) 2022 Published by Elsevier Ltd on behalf of Institution of Chemical Engineers.