Connection between water consumption of apple production and subsurface water depletion on the Loess Plateau of China

Abstract

Economic tree species, particularly those in the agroforestry ecosystems, significantly impact subsurface hydrological processes due to their high transpiration and water demand. Understanding the impacts of agroforestry systems on subsurface water is crucial for sustainable water management, but quantitative regional-scale assessment remains challenging. This study investigated the relationship between water consumption in apple production and subsurface water in the Changwu County on the Loess Plateau of China. Using the dataset of apple orchard areas and yields from 1995 to 2020, we quantified the consumed water and depleted subsurface water by apple production, and subsequently analyzed their relationships with water table. Results indicated a clear linkage between water table decline and water consumption for apple production. Since 2005, precipitation has been unable to meet water demand of apple production, leading to progressive depletion of subsurface water. By 2020, the cumulative water depletion in the study area reached 3.6 × 10⁷ m³, corresponding to a 63 mm decline in the water table depth equivalent to 11 % of mean annual precipitation. Both water consumption for apple production and subsurface water depletion showed linear growth trends in parallel with orchard expansion. The spatial extent of apple orchards was identified as the primary driver of regional subsurface water depletion. Intensive apple production has disrupted groundwater connectivity in this area, thereby increasing the risk to subsurface water. These findings provide valuable insights for balancing sustainable water management and agricultural production.