Impact of deformation response patterns to groundwater level: A post water division project operation in Beijing Plain

The Beijing Plain (BJP), China. With the variable rise of groundwater levels in BJP from 2015 to 2023, deformation patterns and spatio-temporal features have become more complicated. To identify these deformation features and quantify the relationship between deformation and groundwater levels within multiple confined aquifer systems, this study combined K-Shape, BEAST with TFA on basis of the InSAR-derived deformation data. These findings provide scientific support for groundwater management and deformation risk assessment in different deformation pattern regions. Four deformation patterns were identified, including subsidence (Sub), slow subsidence followed by slow rebound (SSFR), slow rebound (SR), and rapid rebound (RR) zones. The Sub zone covered the largest area of 2447 km 2 , while the areas of RR and SSFR were comparable and small with the value of 573 km 2 and 533 km 2 . In RR zone, uplift was driven by groundwater level recovery with an average increase of 23 m in the first confined aquifer, where the lithology is composed of sand-gravel with low clay content. This type of deposits facilitates elastic rebound with high coherence of 0.63 at 6-month timescale and short lag times of about 16 days. In the Sub zone, subsidence is primarily governed by the second and third confined aquifers. This reflects the legacy of intensified deep-groundwater exploitation and is characterized by high gain and significant lag times of about 104 and 109 days for the second and third confined aquifers, respectively. These phenomena are strongly associated with strata lithology and exploitation history in different deformation pattern zones. • Under new hydrological conditions, subsidence and deformation coexist in the BJP. • Surface deformation can be classified into four distinct patterns using K-Shape. • Differential responses of land deformation to groundwater levels among four deformation patterns and aquifer systems. • Explore influencing factors and mechanisms of different deformation patterns.