Applicability of a sharp-interface model for estimating steady-state salinity at pumping wells—validation against sand tank experiments

A numerical sharp-interface model of saltwater and freshwater behavior was validated against experiments conducted in two small scale sand tanks. A simple algorithm was proposed to determine saltwater and freshwater withdrawal rates at a pumping well at which a total pumping rate was specified. Model estimates were compared with transient salinity breakthroughs and steady-state salinities of water extracted from pumping wells in the sand tanks. Experimental scenarios included various combinations of freshwater pumping and injection and saltwater pumping. The corresponding Nash–Sutcliffe model efficiency was 0.95, which showed that the agreement between observations and computed results was satisfactory.

Research highlights
► A sharp-interface model was proposed to estimate salinities of pumped water.
► Model results were compared against sand-tank experiments.
► Scenarios included freshwater pumping and injection and saltwater pumping.
► The model could simulate steady and transient salinities..