Chapter7
Hydrography and Sediment Transport Characteristics
of the Rio de la Plata: A Review
Jorge Lopez Laborde· Gustavo J. Nagy
7.1
Introduction
The Rio de la Plata is located on the East coast of South America, draining the s~cond
largest river basin of the continent and the single largest in terms of population and
economic importance. In a recent paper on definitions and geomorphologic classifications of estuaries, Perillo (1995) classified Rio de la Plata as:
1. a primary estuary, and
2. a river influenced tidal river.
This means, that:
1. the basic form has been the result of terrestrial and/or tectonic processes and the
sea has not changed significantly the original form,
2. due to the high discharge of the tributary rivers, the valley is not presently drowned
by the sea; however, the circulation on the lower portions is highly affected by tidal
dynamics, including reversing currents, resulting in characteristic morphological
patterns, and
3. although it is affected by tidal action, salt intrusion may be limited to the mouth.
In fact, a simple examination of bathymetry, sedimentology and mean salinity distribution charts of the Rio de la Plata system, indicates that it is best defined as "a funnel-shaped coastal plain tidal river with a semienclosed shelf area at the mouth and a
river palaeovalley at the northern coast that favours river discharge and sediment
transport to the adjacent continental shelf".
The present paper reviews previous work on the hydrography and suspended sediment transport characteristics of the Rio de la Plata fluviomarine system. Much of
the previous works has a limited distribution and some of it appears as technical reports, thesis and symposium abstracts. The aim is to consider the basic Rio de la Plata
geomorphological and sedimentological characteristics, as well as salinity and suspended sediment distribution and behaviour, to provide a general description and a
conceptual model, as useful tools for environmental management purposes. New data,
yet to be published, will also be included.
Hydrography and Sediment Transport Characteristics
of the Rio de la Plata: A Review
Jorge Lopez Laborde· Gustavo J. Nagy
7.1
Introduction
The Rio de la Plata is located on the East coast of South America, draining the s~cond
largest river basin of the continent and the single largest in terms of population and
economic importance. In a recent paper on definitions and geomorphologic classifications of estuaries, Perillo (1995) classified Rio de la Plata as:
1. a primary estuary, and
2. a river influenced tidal river.
This means, that:
1. the basic form has been the result of terrestrial and/or tectonic processes and the
sea has not changed significantly the original form,
2. due to the high discharge of the tributary rivers, the valley is not presently drowned
by the sea; however, the circulation on the lower portions is highly affected by tidal
dynamics, including reversing currents, resulting in characteristic morphological
patterns, and
3. although it is affected by tidal action, salt intrusion may be limited to the mouth.
In fact, a simple examination of bathymetry, sedimentology and mean salinity distribution charts of the Rio de la Plata system, indicates that it is best defined as "a funnel-shaped coastal plain tidal river with a semienclosed shelf area at the mouth and a
river palaeovalley at the northern coast that favours river discharge and sediment
transport to the adjacent continental shelf".
The present paper reviews previous work on the hydrography and suspended sediment transport characteristics of the Rio de la Plata fluviomarine system. Much of
the previous works has a limited distribution and some of it appears as technical reports, thesis and symposium abstracts. The aim is to consider the basic Rio de la Plata
geomorphological and sedimentological characteristics, as well as salinity and suspended sediment distribution and behaviour, to provide a general description and a
conceptual model, as useful tools for environmental management purposes. New data,
yet to be published, will also be included.