Hydrodynamics in the huelva estuary:: Tidal model calibration using field data

The scope of the present work is the hydrodynamic study of the Huelva estuary inside an environmental impact project of a possible breaching of a mining sludge waste pond. This study is based on the numerical simulation of the mean river discharge and the tidal effect. The hydrodynamic models were validated against field measurements corresponding to the period in which the experimental data were registered. The measurements in the estuary primarily indicate that the currents oscillate according to the tidal variation along the river and these show that the currents evolve constantly with the tide so that the upstream speed increases until the end of the period of the tide's rising and it subsequently diminishes until a change of direction at the end of the high tide. The speed of the downstream current increases rapidly during the period of maximum descent of the tide and it decreases again until a change of direction at the end of the low tide. Observations and numerical outputs showed an asymmetric trend in the temporal evolution of the speed of the current, reaching the maximum downstream speed approximately 2-3 h later than the high tide, while the maximum upstream speed was produced around 3-4 It later than of the low tide. The downstream current remains lower than the upstream current for the period of time studied and hence results in an upstream current that favors the retention of the hypothetical quantity of water that may be poured into the creek as a result of the rupture of the waste pond.