The Mampituba River drains a watershed with 1,200 km² in area, having its springs in the Serra Geral and debouching to the Atlantic Ocean at city of Torres, after running a 62 km long course. It has a mean discharge of 18.6 m³.s-1, a mean depth around 4 m and is under a microtidal regime. An oceanographic campaign was carried out at May 17th, 2008, when water level, currents, salinity and suspended sediment concentration were recorded during two tidal cycles(25 hours). The water level presented a decreasing trend during the campaign, and the mean tidal range was 0.4 m, with flood dominated asymmetry. The current pattern was bi-directional with mean ebb and flood velocity of 0.33 and 0.13 m.s-1, respectively. The estuarine stratification followed the tide, with the salt wedge intrusion extending 5 km up-estuary. The total salt transport was 1.11 kg.m-1.s-1 out to the estuary. The fluvial discharge component accounted for 98% of the seaward transport, whereas the landward transport had 51% due to the gravitational circulation, 26% due to tidal correlation and 19% due to tidal pumping. The suspended sediments transport was mainly due to the gravitational circulation, which accounted for 83% of the total transport. The Mampituba River estuary hydrodynamics responds mainly to the river, presenting a highly stratified behavior.
circulation; advective transport; transport processes
