Using an analytical solution to estimate the subsidence risk caused by ASR applications

Abstract

Abstract Land subsidence, due to the net compression of one or more semi-pervious clay beds, can be induced by the application of aquifer storage and recovery (ASR) technology. ASR technology involves periodically pumping and injecting water from or into adjacent aquifers for various purposes. In order to estimate the potential risk of aquifer system deformation in response to an injecting-pumping scheme, an analytic solution for the one-dimensional case (a sandwich model) is solved. The solution is analyzed for a unit column of an idealized compressible semipervious layer. A governing equation is invoked that is expressed directly in terms of the vertical displacement of the skeletal frame (Helm, 1987). For simplicity, the saturated aquifer system is assumed to behave like poroelastic material (both recoverable and nonrecoverable). The two idealized aquifers (one above the modeled semi-confining bed and the other beneath) can be pumped independently of each other. Analytical solutions are found for subsidence in response to selected stress/pumping patterns. Results from the analytic solution are applied in order to estimate and predict the potential risk of land subsidence due to ground-water withdrawal and injection, and to provide a first-estimate type of guideline for city and regional planning and the exploration of water resources.