CHAPTER 9 . Geomorphological and Physical Characteristics ofthe Bahia Blanca Estuary
211
Distance from head (km)
36 0
4
8
12
35
a
34
3 _ ,,<::>?>"
33
i- x
"CO
5
<::>.
32
c,'-;'
2
31
30
r' =0.96
29
16
-4
29
30 31
1.0
0.8
0.6
1)
0.4
0.2
0.0
b\
1
<5>
32
33
34
35
36
3N
3S
4N 4S
Fig. 9.9. Mean salinity distribution in the inner reach of the Principal Channel. a cross-section and
tidal averaged salinity; b tidal averaged salinity profiles
Based on the vertical salinity distribution, the estuary may be divided in two sectors (Piccolo et al. 1987):
a an inner region where it behaves as a partially mixed estuary with a strong tendency to be sectionally homogeneous (inner and middle reach), and
b an outer one being sectionally homogeneous with mean salinities values similar
to the adjacent continental shelf ones (Martos and Piccolo 1988; Piccolo et al. 1994).
9.4.4
Tidal Currents
Depth mean longitudinal velocity (u currents for two stations near Ingeniero White
(Fig. 9.10) clearly show a strong asymmetry as indicated by the differences in duration between flood and ebb. The ebb currents (u > 0) are stronger than the flood ones.
The peak. ebb is about twice the maximum flood current in northern station.
The time averaged longitudinal current for the stations located at three sections
along the inner reach are plotted in Fig. 9.11 as a function of the normalized depth
(T/ = z I d). Station I (located near the head of the estuary) is the only one that shows a
net transport towards the mouth of the estuary in all the water column. On the other
hand, stations 3S and 4S (located at 4 and I km headward of Ingeniero White over the
southern flank of the Principal Channel) exhibit a landward net transport. The stations located near the northern flank of the channel show a downstream flow in the
upper third of the water column and upstream in the lower part.
9.4.5
Residual Fluxes
Recent studies of the cross-section distribution of the residual fluxes at the inner and
middle reaches of the estuary (based on the methodology deviced by Perillo and Piccolo 1993,1998) confirm the initial estimations based on the analysis of individual
211
Distance from head (km)
36 0
4
8
12
35
a
34
3 _ ,,<::>?>"
33
i- x
"CO
5
<::>.
32
c,'-;'
2
31
30
r' =0.96
29
16
-4
29
30 31
1.0
0.8
0.6
1)
0.4
0.2
0.0
b\
1
<5>
32
33
34
35
36
3N
3S
4N 4S
Fig. 9.9. Mean salinity distribution in the inner reach of the Principal Channel. a cross-section and
tidal averaged salinity; b tidal averaged salinity profiles
Based on the vertical salinity distribution, the estuary may be divided in two sectors (Piccolo et al. 1987):
a an inner region where it behaves as a partially mixed estuary with a strong tendency to be sectionally homogeneous (inner and middle reach), and
b an outer one being sectionally homogeneous with mean salinities values similar
to the adjacent continental shelf ones (Martos and Piccolo 1988; Piccolo et al. 1994).
9.4.4
Tidal Currents
Depth mean longitudinal velocity (u currents for two stations near Ingeniero White
(Fig. 9.10) clearly show a strong asymmetry as indicated by the differences in duration between flood and ebb. The ebb currents (u > 0) are stronger than the flood ones.
The peak. ebb is about twice the maximum flood current in northern station.
The time averaged longitudinal current for the stations located at three sections
along the inner reach are plotted in Fig. 9.11 as a function of the normalized depth
(T/ = z I d). Station I (located near the head of the estuary) is the only one that shows a
net transport towards the mouth of the estuary in all the water column. On the other
hand, stations 3S and 4S (located at 4 and I km headward of Ingeniero White over the
southern flank of the Principal Channel) exhibit a landward net transport. The stations located near the northern flank of the channel show a downstream flow in the
upper third of the water column and upstream in the lower part.
9.4.5
Residual Fluxes
Recent studies of the cross-section distribution of the residual fluxes at the inner and
middle reaches of the estuary (based on the methodology deviced by Perillo and Piccolo 1993,1998) confirm the initial estimations based on the analysis of individual