Spatial–Temporal Distribution Characteristics of the Water Footprint and Water-Saving Potential of Fruit Trees in Tarim River Basin

It is of great significance to optimize water resource management and promote sustainable development in the Tarim River Basin (TRB) by using the water footprint (WF) evaluation method to evaluate the water shortage of fruit trees in the TRB and analyse its water-saving potential. This study aimed to elucidate the WF spatial–temporal distribution characteristics of fruit trees in the water-limited TRB from 2000 to 2020 and evaluate their water-saving potential capability. The WF was calculated using a combination of irrigation technology simulation and water usage assessments for four different fruit trees (apple, pear, date, and walnut). The results indicate that the green WF (WFgreen) initially increased and then decreased, reaching its lowest value of only 175.09 m3/t in 2020, and decreased by 22.71% from 2000 to 2020. WFblue decreased by 47.13% over the same period. In 2020, the WFblue of date and walnut accounted for a higher percentage of WFblue. WFblue significantly exceeded WFgreen, indicating their high water consumption and the limited adoption of water-saving technologies in the study area. Due to the increase in fruit tree planting area and fertilization, WFgrey exhibited an overall upward trend. Meanwhile, the total WF (WFtotal) indicated a general downward trend, though the walnut tree had the highest WFtotal at 2.21 × 105 m3/t, indicating the popularization of water-saving technology. The results show that, taking 2020 as the baseline, the WFblue of the four fruit trees in the TRB was 2.64 × 105 m3/t (accounting for 89.1%), total WFblue decreased by 0.73 × 105 m3/t (a decrease of 48.38%) after drip irrigation, and the water-saving potential in the five prefectures of the TRB was in the range of 38.55–56.18%. Therefore, the promotion of drip irrigation technology plays a key role in alleviating the water pressure of fruit trees and promoting the sustainable utilization of water resources in the TRB.