Modelling wave climate for Aquaculture Parks in the Philippines. Three larger bays of the Philippines have been investigated for appropriate locations of aquaculture parks. These locations should have limited wave exposure, so that the aquaculture parks can withstand heavy storms. The STWAVE model has been utilized as a tool to predict the wave height based on historical meteorlogical data in areas where there is no or limited wave data collection.

1. STWAVE
Wave Modelling
by
Øyvind Leikvin
Sual, Panabo and Lamon Bay
28.01.2014
© www.akvaplan.niva.no

2. STWAVE – main properties
• assumes constant boundary forcings (wind and
waves), and estimates a stationary solution (steady
state)
• finite-difference model
• is capable of quantitively describing the change in
wave parameters (wave height, period, direction
and spectral shape) between the offshore and the
nearshore
28.01.2014
© www.akvaplan.niva.no

3. STWAVE simulates
• Depth-induced wave refraction and shoaling
• Current-induced wave refraction and shoaling
• Depth-steepness-induced wave breaking
• Diffraction
• Wind-wave growth
• Wave-wave interaction
• Whitecapping
• Reflection
28.01.2014
© www.akvaplan.niva.no

4. STWAVE modeling
- Main input data
• Bathymetry
(provided from oceanographic charts and own measurements)
• Wind speed in model domain
(Long term wind-data extracted from meteorological measurements
from the local area)
• Wave height at the ocean boundary
(Long term offshore wave data retrieved from www.buoyweather.com,
and are extracted from hindcast data from a global WAM wave model)
• Wave energy spectrum
(default by the model/ defined by user)
28.01.2014
© www.akvaplan.niva.no

5. STWAVE modeling;
Panabo, Sual and Lamon bay
Model setup
• Resolution: 100 * 100 m (nesting also possible, for
‘zooming’)
• Whole bays out to the offshore are covered
• Incoming wind and waves from the opening of the
bays (offshore)
28.01.2014
© www.akvaplan.niva.no

6. Results, Panabo
• A georeferenced picture/
map may be a placed as
a background for the
model plot
• A wave train and wind
have been set up,
entering the model
domain from offshore
(165°).
• Typically the whole bay
system and the boundary
towards the open ocean
will be covered
28.01.2014
© www.akvaplan.niva.no

7. Significant wave height, Panabo (Hs)
• Red areas: 0-1 m
• Blue areas: 2 m
(input wave at offshore:
2,1 m)
• Should look at winds
and waves from all
directions, as well as
taking peak periods
into account.
• Reveals possible
places for aquaculture
28.01.2014
© www.akvaplan.niva.no

8. Significant wave height (Hs), from different angles
165
deg
180
deg
195
deg
210
deg
28.01.2014
© www.akvaplan.niva.no

9. The STWAVE model also simulates the
directional spreading of the waves into the bay:
28.01.2014
© www.akvaplan.niva.no

10. Results, Sual
• Wave Height (Hs)
• A wave train and wind
are set up, entering the
model domain from
offshore, from about
320-340°.
28.01.2014
© www.akvaplan.niva.no

11. Results, Lamon Bay
• Wave Height (Hs)
• A wave train and wind
are set up, entering the
model domain from
offshore, from about
30-45°.
28.01.2014
© www.akvaplan.niva.no

12. Why STWAVE :
Finding new aquaculture sites
28.01.2014
© www.akvaplan.niva.no

13. How to use the wave modeling results:
 Finding new and appropriate areas for aquaculture
– Shelter (wind & waves)
– Depth
 Exposure classification (wave height)
 Choice of
–
–
–
–
28.01.2014
cage technology
structure
design
insurance
© www.akvaplan.niva.no

14. MARAMING
SALAMAT
!
28.01.2014
© www.akvaplan.niva.no