Analysis of Aquifer‐System Deformation in the Doñana Natural Space (Spain) Using Unsupervised Cloud‐Computed InSAR Data and Wavelet Analysis.

This work is focused on the Almonte‐Marismas aquifer located within Doñana Natural Space (SW Spain); this aquifer is threatened by droughts, irrigation‐driven groundwater overexploitation, urban use, and the potential reactivation of gas extraction and storage projects. We present ground deformation measurements from Sentinel‐1 Interferometric Synthetic Aperture Radar (InSAR) data ranging from 1 to 2.5 cm, covering ∼2,500 km2 from 2014 to 2020. Detecting spatially distributed ground deformation over this agricultural area is challenging due to the low‐coherence radar signals; consequently, the ground movement results are on the same order of magnitude as the errors associated with InSAR data. We have approached this issue by considering auxiliary information such as groundwater levels, climatic time series, and pumping rates and analyzing their spatio‐temporal connections to ground displacements. We correlate InSAR and hydrogeological information through wavelet analysis, developing a Python package that allows applying the same methodology in other similar study areas. For the first time in the Doñana area, a significant relationship between distances to pumping wells and the displacement extent is detected. Moreover, other subsidence‐related triggering factors are identified, such as the soil moisture balance, clay shrinking‐swelling processes, and creep of geological formations. These results are highly valuable to support aquifer management decisions in the Doñana Natural Space; in this border region, three groundwater bodies were officially declared overexploited in 2020. Our findings provide a ground motion baseline assessment to help differentiate historical variations from any future anthropogenic effect in this complex marsh land ecosystem. Plain Language Summary: This work is focused on Doñana Natural Space (SW Spain), which integrates the Doñana National Park and the Doñana Natural Park in a single space. Doñana has acquired the highest protected area categories that a natural area can receive from international conservation organizations. However, Doñana's ability to support biodiversity is under constant threat due to droughts, groundwater overexploitation for irrigation, urban use, and the reactivation of a gas extraction and storage project. This study presents ground deformation measurements in the Doñana area derived from Earth observation data ranging from 1 to 2.5 cm from 2014 to 2020. The work relates ground displacement, groundwater and climatic information through mathematical tools. For the first time in the Doñana area, a significant relationship between distances to pumping wells and the displacement extent is detected. These results are highly valuable to support aquifer management decisions in the Doñana Natural Space. Our findings provide a ground motion baseline assessment that will help differentiate historical variations from any future anthropogenic effect in this complex marsh land ecosystem. Key Points: Integrated Interferometric Synthetic Aperture Radar and hydrogeological analysis has shown displacements up to 2.5 cm/year on the aquifer that hosts the Doñana Natural SpaceWavelet method with a new Python package allows for integrated displacement, groundwater level, climatic and pumping time series analysesThe results provide a ground motion baseline to differentiate natural variations from future anthropogenic effects in the Doñana area [ABSTRACT FROM AUTHOR]