Ecoinformatics Problems of the World Ocean - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 339

4.10 Estimation of Oil Hydrocarbon Pollution Parameters
in Sea Water

The problem of identi cation and assessment of oil pollution parameters in the

water environment has been studied suf ciently. The existing methods of oil dis-

covery in the water may be divided into two groups, surface film and suspension,

corresponding to the state of the oil hydrocarbons. The oil and oil products, by their
physical-chemical properties, can form water

films, clots, emulsions, and solutions

in the sea. The oil films have thicknesses from fractions of a millimetre to several

centimetres. All this determines the methods of oil pollution monitoring.
The choice of monitoring method is determined by the oil pollution level. It is
known that oil pollution exercises in

fl uence on the physical-chemical processes

taking place in the sea water. Speci cally, the surface strength for oil and oil

products is two-four times less than for non-polluted water. The thermal conduc-
tivities and thermal capacities of water and oil are distinct and equal respectively to
0.599 W m − 1 K − 1 and 4.187 kJ kg − 1 K − 1 for water and to 0.15 W m − 1 K − 1 and 1.7

-

2.1 kJ kg − 1 K − 1

for oil. These distinctions in fl uence the many processes in the

atmosphere-water system. Oil pollution films decrease thermal conductivity and

thermal capacity of the upper sea layer. They change the evaporation process
decreasing it by 1.5 times or more, they disturb the gas exchange between the
atmosphere and sea water, and they change the water temperature. All these effects
are used for the design of measuring devices to estimate the oil pollution level
(Klyuev 2000; Marhaba et al. 2000). Microwave methods are described by
Krapivin (2000). Inhere we consider optical methods.
On a level with the above mentioned effects of sea water oil pollution there
exists an optical effect which is determined by the change in sea surface albedo and
by the variation of the interior optical properties of sea water. Theoretical
approaches to the problem of light spreading in the sea water environment or its
re ection from the sea surface are connected with the consideration of various

tasks. For example, calculation of the re

fl

cient under different sea
environment states is given by Kabanov et al. (2000). Theoretical and experimental
studies show the existence of contrasts in the re

fl ection coef

films and a
non-polluted water surface (Fig. 4.32 ). Certainly, these contrasts are functions of
many parameters: wavelength, oil

fl ecting properties of oil

film thickness, vision angle, salinity, water
roughness, light intensity, and content of other contaminants. As shown by Hong
et al. (1994), the use of spectral measurements at a range of 380

700 nm allows one
to have a reliable technique for the detection of oil pollution on the water surface.
The Adaptive Identi

-

er is designed on the principle shown in Figs. 9.11 and 9.12

. Adaptive Identi er consists of a multi-channel device registering the light scat-

tered in the water or re

ected from the surface in the visible range, of an infor-
mational interface and of software. The principle of the functioning of the system
consists in the registration in numerical code n

fl

∈ [7, 128] of spectra {T n ( ʻ ): ʻ∈ [ ʻ i , ʻ i

+1 ], i =0,1,

1} on the basis of which the solution about the existence of oil
pollution is taken and the assessment of its parameters is realized. Speci

… , n −

cally, for