Water-energy-carbon emissions nexus analysis of crop production in the Tarim river basin, Northwest China

The water-energy-carbon emissions (WEC) nexus plays an important role in the sustainable production of crops. Changes to cropping patterns, along with an increase in water and energy demand and rising pressure to reduce carbon emissions, are severely challenging the WEC nexus in the Tarim River Basin (TRB). This study establishes the WEC nexus framework in crop production by analyzing spatio-temporal variations in key indicator trends using the footprint and nexus approach. The study also evaluates the coupling coordination development level of the WEC system based on the coupling coordination degree model. The results reveal the following: (1) The TRB is dominated by blue water irrigation resources, which account for 90% of total water consumption (AWC). There was an overall trend of increasing energy inputs per hectare for major crops in the TRB during 1990–2019. In particular, the energy input per hectare in Bayingol increased significantly and reached the highest level in 2016, at 4.39 × 104 MJ ha−1. Meanwhile, carbon footprint (CF) exhibited obvious spatial differences at the basin scale. Kizilsu Kirghiz had the lowest average CF, at 0.79 kg CO2_eq·kg−1. (2) The coupling degree of the WEC system in the study area is greater than 0.8, maintaining high-level coupling. The coupling coordination degree of Kizilsu Kirghiz had a clear upward trend and was stable at high levels during 2009–2019. (3) Cropping patterns are an important factor affecting the coupling coordination development of the WEC system. Strengthening connections among various sectors and improving energy utilization efficiency are critical actions to promote the low-carbon transition of crop production. This study provides the latest reference for realizing the coordinated development of the WEC system in the TRB.