Analysis of factors influencing groundwater drought in the Loess zone of China

Understanding the characteristics and factors influencing groundwater resources is important for regional water resources management. The Gravity Recovery and Climate Experiment (GRACE)-based groundwater conditions were used to analyze the spatiotemporal characteristics of and the factors influencing groundwater storage (GWS) distribution in the Loess zone of the Yellow River Basin. The results revealed that the spatiotemporal distribution of GWS anomalies in the Loess zone of China was best explained by the first three components of the empirical orthogonal function (EOF), representing 85.6% of the total variance. The normalized difference vegetation index (NDVI) was significantly correlated with groundwater drought (<i>p</i> < 0.05). In addition, NDVI and evapotranspiration (ET) were the dominant factors influencing groundwater drought. NDVI was the dominant influencing factor in 67% and 80% of the total study area between 2002-2014 and 2015-2021, respectively. This study provides important guidance for a future ecological restoration plan in the Loess zone.