Mechanisms of irrigation water recharge in the Kongque River Irrigation District of Xinjiang, China

Understanding the infiltration process and quantifying recharge are critical for effective water resources management, particularly in arid and semi-arid regions. However, factors influencing on recharge process under different land use types in irrigation districts remain unclear. In this study, a Brilliant Blue FCF dye tracer experiment was conducted to investigate infiltration pathways under the cotton field, pear orchard, and bare land conditions in the Kongque Rive Irrigation District of Xinjiang, China. Recharge rates were estimated using the chloride mass balance method. The results show that the average preferential flow ratio was highest in the bare land (50.42%), followed by the cotton field (30.09%) and pear orchard (23.59%). Matrix flow was the dominant infiltration pathway in the pear orchard and cotton field. Irrigation method was a primary factor influencing recharge rates, with surface irrigation promoting deeper infiltration compared to drip irrigation. Under the drip irrigation mode, the recharge of cotton fields ranged from 23.47 mm/a to 59.16 mm/a. In comparison, the recharge of surface irrigation in pear orchards contributed between 154.30 mm/a and 401.65 mm/a. These findings provide valuable insights into soil water infiltration and recharge processes under typical land use conditions in the Kongque River Irrigation District, supporting improved irrigation management and sustainable water resource utilization.