CHAPTER 7 • Hydrography and Sediment Transport Characteristics of the Rio de la Plata
143
240
220
200
180
E 160
~
'" 140
10
:v 120
c
10 100
~
- 10 80
'" <11
'0
60
i=
40
20
Hour 0 is 5/24/81
0
0
24
48
72
96
120
144
Hours
290 - 1 Hour 0 is 3/20/82
270
250
230
E210
~
'" 190
~
10 170
C
10 150
~
"'
130
'" (lJ
'0 110
i=
90
70
50 0
24
48
72
96
120
144
188
212
Hours
Fig. 7.6. Local wind effects at Mantaras tidal station (34°5336"S to 56°11'54"W, Bahia de Montevideo);
a 96-h descent related to 16 up to 20 knots ESE-SSW winds, and a 132-h rise related to 10 up to 20 knots
NNE-NNW winds
The effect of the wind on the upper Rio de la Plata water surface, as studied by Balay
(1961), is shown on Fig. 7.5. Figure 7.6 presents local wind effects at Mantaras tidal station, located at 34°53'36"5 to 56°n'54"W (Montevideo Bay) and Fig. 7.7 shows yearly
wind direction distribution for some selected weather stations. Mazio and Martinez
(1989) provided information about the wind effect at Torre Oyarvide: the water level
decreases under the influence of N, NE and W winds and increases with 5, 5E and 5W
winds. For E and W winds, the water level can either increase or decrease, depending
on the direction of the wind rotation.