Exploring the Relationship between Land Subsidence and Precipitation in the Lebna Watershed in Tunisia Using SBAS-InSAR Analysis

In this study, we explore the relationship between ground subsidence acceleration and precipitation fluctuations in the Cap-Bon peninsula in northern Tunisia. Our findings reveal that this phenomenon shows uneven trends in relation to the terrain, as well as the types of vegetation and land use in the area. The analysis of the Interferometric Synthetic Aperture Radar (InSAR) ground subsidence deformation time series is considered within two critical periods for the region between 2018-2019 and 2021-2022. Results reveal distinct non-uniform subsidence in Cap-Bon peninsula, with more pronounced effects observed in the irrigated area of Zaouiet Jedidi, reaching a maximum subsidence rate of -19.62 cm/year. This area is known to be protected because of its importance for the agricultural production of citrus fruits on a national level. Then, after a thorough examination of the factors contributing to subsidence, it has been established that the uneven deformation is mainly due to the over-exploitation of groundwater within a relatively dry period.