Modeling the two- and three-dimensional displacement field in Lorca, Spain, subsidence and the global implications

Abstract

Land subsidence associated with overexploitation of aquifers is a hazard that commonly affects large areas worldwide. The Lorca area, located in southeast Spain, has undergone one of the highest subsidence rates in Europe as a direct consequence of long-term aquifer exploitation. Previous studies carried out on the region assumed that the ground deformation retrieved from satellite radar interferometry corresponds only to vertical displacement. Here we report, for the first time, the two- and three-dimensional displacement field over the study area using synthetic aperture radar (SAR) data from Sentinel-1A images and Global Navigation Satellite System (GNSS) observations. By modeling this displacement, we provide new insights on the spatial and temporal evolution of the subsidence processes and on the main governing mechanisms. Additionally, we also demonstrate the importance of knowing both the vertical and horizontal components of the displacement to properly characterize similar hazards. Based on these results, we propose some general guidelines for the sustainable management and monitoring of land subsidence related to anthropogenic activities.

Modeling 3D Free-geometry Volumetric Sources Associated to Geological and Anthropogenic Hazards from Space and Terrestrial Geodetic Data

“…Over the past few decades, an explosion in the quantity and quality of geodetic data has been increasingly applied to geological and anthropogenic hazards [1][2][3][4][5][6][7]. It includes ground-, air-and space-based observations that span a range of spatial and temporal resolutions.…”

“…It includes ground-, air-and space-based observations that span a range of spatial and temporal resolutions. The development of space geodetic techniques has been particularly important to the measurement of surface displacements, resulting in a sharp increase in the number of active areas where deformation has been detected [5][6][7][8][9]. These new sensitivities and capabilities have produced the need for new approaches for analyzing, modeling and interpreting geodetic data [4,5].…”

“…Simultaneously, the rapid growth of the global population concentrated in large cities has led to significant increase in risks when such highly populated areas are also subject to natural (e.g., flood, volcanic and seismic activity) and anthropogenic hazards [4][5][6][7][10][11][12][13][14]. Improving our understanding of the processes associated with these geological and anthropogenic hazards is crucial for developing systems that monitor and evaluate them, as well as to aid decision makers during a crisis.…”

“…Additionally, land subsidence, ranging from local collapse to the broad regional lowering of Earth's surface, represents the main geomechanical effect related to the removal of subsurface support [5]. Subsidence can occur as a result of (i) natural factors (e.g., tectonic activity, self-consolidation of recent sedimentary deposits, oxidation and shrinkage of organic soils) [18,19], and (ii) anthropogenic processes (e.g., groundwater pumping [20][21][22][23], urban development [24], hydrocarbon or mining exploitation [25,26]).…”

“…Advances in computing power have facilitated rapid development of numerical methods that are capable of both incorporating material and structural heterogeneity [31,32] and investigating the characteristics of the subsurface [33]. They can even be used in inverse approaches [34], blurring the lines between the traditional "inverse" and "numerical" categorizations [5].…”