breakwater in the middle part of the ria, showing an anthropogenic influence on the circulation in the ria. The presence of a dam in the river
Mero, the main river in this area, has also some influence on the general
circulation of the ria. Varela etal. (1994) have shown that, with the present
river discharge, the ria can be considered a coastal bat' instead of a rfa, in
the sense that the oceanic influence is the most important one.
Area under scope
The Ria of La Coruna is one of the 17 Galician rias located on the NW
coast of the Iberian Peninsula. It has a north-south orientation with a
length of only 5 kilometres. The Rfa of La Coruna communicates with
the coastal shelf by means of a mouth located in the northern part of
the estuary. This mouth is 3 km wide and has an average depth of 25
metres. The mean volume of water in the rfa is of about 251 x 10
6 cubic
metres. The main freshwater run-off, corresponding to the river Mero, is
located in the innermost part of the estuary 1 . This river, according to
data from the Confederaciôn Hidrogrâfica del Norte de Espana, had an
average discharge of 8.2 ± 2.5 m’.s
1 over the period 1940-1987 (Vergara
& Prego, 1997). A breakwater was built in the westem coast in order to
protect the harbctur area. /V plot of the shoreline can be seen in figures
la (year 1918) and lb (at present).
Figure 1 - Rîa of La Coruna in (a) 1918 and (b) 1996. S| and Sn represent the sections were residence time wil
be calculated.
The river Mero has a watershed of 345 km
2 and an annual precipitation
of 996 millimetres. The main source of water in this basin is the rain
(Rio-Barja & Rodriguez-Lestegas, 1992), which induces a level in the
river depending on the rainfall pattern. Thus, the maximum river discharge under pristine conditions was found in January (18 m’.s
6 ), and
the minimum in August (1 m
3 .s
4 ). The building of the Cecebre dam, in
1976, has changed this natural situation. A study of the data of the Confederaciôn Hidro-grâfica del Norte de Esparia shows that the seasonal
257
Mero, the main river in this area, has also some influence on the general
circulation of the ria. Varela etal. (1994) have shown that, with the present
river discharge, the ria can be considered a coastal bat' instead of a rfa, in
the sense that the oceanic influence is the most important one.
Area under scope
The Ria of La Coruna is one of the 17 Galician rias located on the NW
coast of the Iberian Peninsula. It has a north-south orientation with a
length of only 5 kilometres. The Rfa of La Coruna communicates with
the coastal shelf by means of a mouth located in the northern part of
the estuary. This mouth is 3 km wide and has an average depth of 25
metres. The mean volume of water in the rfa is of about 251 x 10
6 cubic
metres. The main freshwater run-off, corresponding to the river Mero, is
located in the innermost part of the estuary 1 . This river, according to
data from the Confederaciôn Hidrogrâfica del Norte de Espana, had an
average discharge of 8.2 ± 2.5 m’.s
1 over the period 1940-1987 (Vergara
& Prego, 1997). A breakwater was built in the westem coast in order to
protect the harbctur area. /V plot of the shoreline can be seen in figures
la (year 1918) and lb (at present).
Figure 1 - Rîa of La Coruna in (a) 1918 and (b) 1996. S| and Sn represent the sections were residence time wil
be calculated.
The river Mero has a watershed of 345 km
2 and an annual precipitation
of 996 millimetres. The main source of water in this basin is the rain
(Rio-Barja & Rodriguez-Lestegas, 1992), which induces a level in the
river depending on the rainfall pattern. Thus, the maximum river discharge under pristine conditions was found in January (18 m’.s
6 ), and
the minimum in August (1 m
3 .s
4 ). The building of the Cecebre dam, in
1976, has changed this natural situation. A study of the data of the Confederaciôn Hidro-grâfica del Norte de Esparia shows that the seasonal
257