Author(s): Albert Herrero; Allen Bateman; Vicente Medina
Keywords: Density currents; mercury; numerical model; resuspension; temperature
Abstract: Density currents occur in lakes and sea environments when two masses of water interact giving rise to a relative movement between them. Depending on the initial and boundary conditions, turbulence associated with them is able to lift the sediment. This fact can be a problem in places where the sediment is contaminated due to industrial activities. In 2001, a pollution episode occurred in the Flix reservoir (Tarragona, Spain), in which thousands of fish died and the water supply of cities such as Tarragona was affected. This study analyses the possibility of a density current due to a temperature difference as the explanation for this event. The previously developed one-dimensional, Lagrangian model BANG 1D of subaqueous turbid surges has been modified to incorporate temperature evolution. The obtained results show that a temperature difference can generate a density current that is able to resuspend the sediment although the grade of erosion highly depends on the initial velocity of the current.