paper presents work done utilizing Radarsat fine mode data to model the tidal
current component effects on oil spills spreading. In this study, the utility of
oil spills detection is examined using fractal dimension methods. The finite
difference model is used to simulate the tidal current velocity from Radarsat
data. The tidal current velocity modeled by using a finite difference model of
Doppler shift frequency. The current velocity components are modeled by applying
Lagarangian interpolation. The statistical model is used to find out the
significant correlation between tidal current components and oil spills
The results show the tidal current components have effects on
the oil spills spreading. The northward tidal current components are effected
the length of the oil spills while the eastward components are effected the
width of oil spills.
In conclusion, Radarsat data has good potential for
oil spills detection and mapping. Radarsat data could be used to model the tidal
speeds and their effects on oil spill patterns. The tidal current components are
in good correlation with oil spill lengths and widths.
Modeling of oil spills movements by remote
sensing is in early stage of investigation. Up to now the scientists could not
be used the full capability of remote sensing techniques for modelling and
predicting oil spill movements. Using remote sensing techniques for oil spill
detection was just focused on the improvement of detection algorithms. These
studies cannot provide any sufficient information for identification the effects
of physical parameters (wind, current, waves…etc.,) on the oil spill patterns.
modelling of water movement on radar data effects have been studied by Maged and
Ibrahim . They found that the strong tidal current induced the large oil
spill width. Maged  modelled the ship speed effects on oil spill spreading.
Maged  found that the increases of oil spill lengths are due to the effect of
ship wakes. As the ships created a turbulent area along the oil spill tracks.
This study aims to model the effect of tidal current components on oil
spill patterns (width and length) on Malacca Straits. This is because of the
fact that tidal current movements considered significant in narrow waterway such
as the Malacca Straits, which is a near 12 hourly sinusoidal phenomenon arising
from the semi-diurnal motion of the M2 and S2 tidal components.
The study area is located
in the Malacca Straits between 102° 16' E to 103° 48' E and 1° 16'N to 2° 13' N.
According to Wyrtki  the water movements are in general directed towards the
northwest direction and are strongly related to the surface gradient of the sea
level. Furthermore, Wyrtki  stated that the period of strongest flow is from
January to April, during the northeast monsoon with current velocity of 0.95
Oil spills Detection
According to Benelli and
Garzelli  the fractal dimension could be estimated from power spectra. This
means that fractal dimension can be characterized by a random-phase Fourier
description in the form of power density. The power density can given by
P (W1,W2) = 1/[ÖW12+W22]b (1)
where W is the
frequency domain of the Fourier Transform and b= 2H +2 as H is Hurst or
persistence parameter, controlling the roughness of the surface. H is 1
corresponding to smooth surface and H is zero which corresponding to a very
rough texture. The fractal dimension D and persistence parameter are related by
D = 3-H (2)
Thus D can be computed by applying
a linear regression on log [P(W1,W2)] vs. Log [ÖW12, ÖW22]. Furthermore, H can
be computed from the linear regression of ratios of powers.