14.2 Tides and Waves in Mangrove Forests
§ 0.0
-5
.g -0.2
~
~
-0.4
-0.6
-0.8
-l.0
0.00
_ _ _ mean water leJiel_
-
-
-
-I
X = 25 1
1
I
I
I
I x=O
I
0.05
- - horizontal vel.
- - vertical vel.
0.10
0.15
0.20
423
0.25
0.30
Mean amplitude of velocity (mJs)
Fig. 14.4: Calculated vertical profiles of the mean amplitudes of horizontal and
vertical components of orbital velocity at cross-sections (J: = 0 m, 25 m, 50 m) in
a very dense forest; at x = 50 m the vertical velocity is negligibly small and is not
shown (adapted from Massel et al., 1998)
mean amplitudes of horizontal, 71, and vertical, iii, components of velocity at
three cross-sections in a mangrove forest are shown in Fig. 14.4. In this case,
the ratio of wavelength to water depth is relatively large, L/h = 16 and the
profiles of both velocity components are almost vertically uniform. They attenuate very quickly with distance from the mangroves front, and behind the
mangroves they are negligible.
Field Experiments. Observations of physical processes in tropical mangrove
forests are very sparse. Two field experiments were conducted at Cocoa Creek
in Australia and at Nadara River on Iriomote Island, Japan, during January
and February of 1997. Species distributions at these two locations are shown
in Fig. 14.5, and a detailed description of these sites and the observational
techniques used at each location are given by Brinkman et al. (1997).
Time series of water surface elevation recorded at various locations along
the transects at both study sites were analyzed for basic statistical and spectral quantities (for details see Brinkman et al., 1997). Here we examine the
wave propagation through a mangrove forest in terms of the normalized energy,
Enorm(x), as defined by Eq. (14.4). Values of Enorm(x) calculated from field data
at various distances into the forest at Cocoa Creek are shown in Fig. 14.6. These
data show an obvious decline in wave energy transmission with distance into
the forest. Normalized energy value, Enorm(x), was calculated using incident
§ 0.0
-5
.g -0.2
~
~
-0.4
-0.6
-0.8
-l.0
0.00
_ _ _ mean water leJiel_
-
-
-
-I
X = 25 1
1
I
I
I
I x=O
I
0.05
- - horizontal vel.
- - vertical vel.
0.10
0.15
0.20
423
0.25
0.30
Mean amplitude of velocity (mJs)
Fig. 14.4: Calculated vertical profiles of the mean amplitudes of horizontal and
vertical components of orbital velocity at cross-sections (J: = 0 m, 25 m, 50 m) in
a very dense forest; at x = 50 m the vertical velocity is negligibly small and is not
shown (adapted from Massel et al., 1998)
mean amplitudes of horizontal, 71, and vertical, iii, components of velocity at
three cross-sections in a mangrove forest are shown in Fig. 14.4. In this case,
the ratio of wavelength to water depth is relatively large, L/h = 16 and the
profiles of both velocity components are almost vertically uniform. They attenuate very quickly with distance from the mangroves front, and behind the
mangroves they are negligible.
Field Experiments. Observations of physical processes in tropical mangrove
forests are very sparse. Two field experiments were conducted at Cocoa Creek
in Australia and at Nadara River on Iriomote Island, Japan, during January
and February of 1997. Species distributions at these two locations are shown
in Fig. 14.5, and a detailed description of these sites and the observational
techniques used at each location are given by Brinkman et al. (1997).
Time series of water surface elevation recorded at various locations along
the transects at both study sites were analyzed for basic statistical and spectral quantities (for details see Brinkman et al., 1997). Here we examine the
wave propagation through a mangrove forest in terms of the normalized energy,
Enorm(x), as defined by Eq. (14.4). Values of Enorm(x) calculated from field data
at various distances into the forest at Cocoa Creek are shown in Fig. 14.6. These
data show an obvious decline in wave energy transmission with distance into
the forest. Normalized energy value, Enorm(x), was calculated using incident