“…Assimilation of measured soil water content (SWC) into model runs is frequently used to improve the prediction of soil water at future times by land surface models (e.g., Liu & Gupta, 2007; Montaldo & Albertson, 2003; Reichle, Crow, & Keppenne, 2008; Reichle, Koster, Dong, & Berg, 2004) and hydraulic models (e.g., Crosson, Laymon, Inguva, & Schamschula, 2002; Sun, Zhang, & Li, 2011; Tian et al., 2017). In general, the surface soil water content (2–10 cm) derived from remote sensing is assimilated, which considers both measurement and prediction uncertainty (e.g., Greifeneder, Notarnicola, Bertoldi, Brenner, & Wagner, 2015; Montaldo, Albertson, & Mancini, 2007). Many studies have demonstrated improvements in predicting vertical soil water distribution by assimilating remotely‐sensed surface soil water content in hydrological models (e.g., Liu, Wang, & Hu, 2017), but the improvement varied greatly with soil depth, e.g., smaller improvement in deeper soil layers (Heathman, Starks, Ahuja, & Jackson, 2003; Wang, Liu, Kou, & Lu, 2012).…”