SEDIMENT RESUSPENSION BY WIND IN A SHALLOW LAKE OF ESTEROS DEL IBERÁ (ARGENTINA): A MODEL BASED ON TURBIDIMETRY,

A model based on empirical relationships is used to study frequency and magnitude of the sediment resuspension by wind-induced waves. The model has been developed for Laguna Galarza, a mesotrophic round-shaped shallow lake of Esteros del Iberá wetland. Given the logistic and accessibility difficulties of this pristine macrosystem, the installation of field autonomous stations facilitated the continuous data acquisition. Using the surface wave theory, a daily spatial model of resuspension was built from simultaneous hourly time series of infrared nephelometric turbidity and speed and direction of wind. The model was also used to predict total suspended solids in another lake of the wetland (Laguna Iberá) showing a good agreement with observed field values, even although Laguna Iberá has a more irregular contour and a eutrophic state. Finally, we apply the model to discuss about the ecological impacts of resuspension on the distribution of the shore communities and to characterize the composition of the particulate suspended matter of the limnetic ecosystem. The model was especially practical to simulate the possible implications of the alterations of the water level into the resuspension regime