Cattani, P.E. and Lamour, M.R., 2016. Considerations regarding sedimentation rates along the E-W axis of the Paranaguá Estuarine Complex, Brazil: A bathymetric approach.
The sediment dynamics in coastal regions are a result of the coexistence of fluvial, estuarine, deltaic, and shelf depositional environments, as well as the relation among the processes of sediment transport. The Paranaguá Estuarine Complex (PEC) presents different characteristics along its E-W axis, containing areas of port activity. The aim of this study was to identify critical areas of estuarine sedimentary infill and determine their rates and relationships regarding the estuarine environment features. This study employed 38 bathymetric surveys conducted between 1999 and 2008 arranged sequentially from the head of the estuary to the inner continental shelf. Initially, these surveys were grouped chronologically and according to their areas of overlap. Later, they were divided according to grain size and short-term hydrodynamic behavior in four sectors. The sedimentation rates in a portion of the estuary head were 0.60 cm·mo−1·km−2, whereas in the turbidity maximum zone (TMZ), they were approximately 0.06 cm·mo−1·km−2, and in the estuary mouth, they were 0.08 cm·mo−1·km−2. On the inner continental shelf (ICS), a critical area of silting on the terminal lobe of the ebb tidal delta was quantified as 0.56 cm·mo−1·km−2. The differences among silting rates along the PEC are related to the sediment supply for each sector of deposition, as well as the acting hydrodynamic forces. The higher rates found in the inner portion of the estuary may be the result of the advance of river deltas at the head of the estuary, associated with shallow depths and low energy in tidal currents. In the TMZ, silting occurs heterogeneously, with erosion areas associated with rock formations. On the ICS, the area of critical concern in sediment dynamics is the ebb tidal delta, located at the mouth of the PEC, where shallow areas amplify the power transport of the wave energy from the S-SE quadrant , and this energy decreases when entering the channel, allowing deposition.