Enayam Port

Tamil Research Institute
RAPID TECHNO-ECONOMIC FEASIBILITY REPORT FOR
DEVELOPMENT OF COLACHEL PORT AT TAMILNADU
FINAL REPORT
(GEBCO, http://www.gebco.net). The bathymetric portion was generated by combining quality-controlled
ship depth soundings, with predicted depths between the sounding points guided by satellite-derived
gravity data [Smith and Sandwell, 1997].
More than 60 years of historical wind-generated offshore waves were performed for the last half century.
The wave hindcast outcomes provide hourly time series of significant wave height, mean wave period,
peak frequency and mean wave direction for all the grid points of the computed grid. More details can be
found in Reguero et al. 2012.
2.3. THE CORRECTION PROCEDURE OF THE GOW GRID-POINT.
In order to reduce possible discrepancies of numerical results with respect to the instrumental data, a
correction procedure using satellite info has been applied to the GOW significant wave height. The
discrepancies could be due to flaws in the wind fields, insufficient model resolution, unresolved island
blocking, imperfect bathymetries, etc.
The applied calibration technique is a parametric method based on a nonlinear regression problem.
Briefly, the correction parameters vary smoothly along the possible directions by means of cubic splines,
allowing different corrections depending on the direction. Corrections are made on empirical quantile
information on a Gumbel probability paper scale giving more relevance on the calibration procedure to
the maximum data, which is more important from the design point of view. A detailed description of the
methodology can be found in Minguez et al., 2011.
2.4. THE GOT (GLOBAL OCEAN TIDES) DATABASE.
GOT dataset provide hourly time series of astronomical tide for a selected period. It is generated using
the harmonic constants derived from the TPXO7.0 global tides model developed by Oregon State
University (http://volkov.oce.orst.edu/tides/global.html).
TPXO7.0 is a current version of a global model of ocean tides, which best-fits, in a least squares sense, the
Laplace Tidal Equations and along track averaged data from TOPEX/Poseidon and Jason (on
TOPEX/POSEIDON tracks, since 2002). The methods used to compute the model are described by Egbert
et al. (1994) and further detail is provided by Egbert and Erofeeva (2002). The database includes eight
primary constants (M2, S2, N2, K2, K1, O1, P1, Q1), two long period constituents (Mf, Mm), and 3 nonlinear
(M4, MS4, MN4) harmonic constituents, provided in a global grid of 1440 x 721 points, at 1/4
degree resolution full global grid. This information is used to reconstruct hourly time series of tide in any
location worldwide using the tool t_tide (Pawlowicz et al., 2002).
3. REANALYSIS DATABASES
This information has been extracted from two locations points with hourly temporal resolution:
• Southwest India [Lon=76.50ºE, Lat=8.00ºN]
• Southeast India [Lon=78.00ºE, Lat=8.00ºN]
The databases contain met-ocean information with hourly time series of several parameters of the sea
state, wind speed and wind direction and sea level variability due to tide:
CP1832-FR-AX-02-CP-WaveClimate-Ed1.docx AX02 - 3
www.tamilri.com