International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004 
  
dissolved in water and even oxidize, and yet some undergo 
bacterial changes and eventually sink to the bottom by 
gravitational action. The soil is then contaminated with a gross 
effect upon the terrestrial life. As the evaporation of the volatile 
lower molecular weight components affect aerial life, so the 
dissolution of the less volatile components with the resulting 
emulsified water, affects aquatic life (Akpofure et al, 2000). Once 
Oil is released on water, the process of spreading takes place 
immediately. This process stands to be the most significant. Some 
forces influence the lateral spreading of oil on even calm water. 
These forces include: 
(a.) Gravitational force which brings about decrease in film 
thickness. 
(b.) Surface tension and inertial forces. 
The force of gravity is found to be proportional to the film 
thickness, the gradient thickness and the density difference 
between the oil and water. The surface tension causes co-efficient 
of spreading which gives the difference between air/oil and 
oil/water surface tensions. This force that is independent of the 
film thickness is the dominant process gotten in the final phase of 
spreading. 
The inertia of the oil body and the oil/water friction causes 
retardation on the surface tension. The inertia of a specific oil 
slick, which is a function of the density and thickness, readily 
diminishes alongside spreading. Another factor that affects 
spreading is water temperature (Akpofure et al, 2000). 
The spreading of an oil slick is one of the most important 
processes in the early stage of the oil slick transformation, 
because of the influence of the surface area of the oil slick on 
weathering processes such as evaporation and dissolution. The 
balance between gravitational, viscous and surface tension forces 
determines the spreading of an oil slick. The spreading of an oil 
slick passes through three phases. In the beginning phase, the 
gravity and inertia forces are balanced. In the intermediate phase 
the gravity forces are balanced by viscous force. In the final 
phase, the surface tension force is balanced by viscous force. 
Fay considered an oil slick to pass through three phases of 
spreading. Immediately after the spill, the oil slick is rather thick. 
Therefore, in the first phase, gravity and inertia forces dominate 
the spreading process with gravity being the accelerating force 
and inertia the retarding force. As time progresses, the oil slick 
becomes thin and inertia forces become relatively unimportant. In 
the second phase the gravity and viscous forces dominate the 
spreading with viscous force being the retarding one. As the slick 
gets thinner, interfacial tension forces become important. A third 
phase is reached in which interfacial tension and viscous forces 
dominate the spreading (Reddy and Brunet, 1997) 
5.0 MANAGEMENT OF OIL SPILLS 
A number of laws already exist in the Nigerian oil industry. Most 
of these laws provide the framework for oil exploration and 
exploitation. However, only some of these laws provide 
guidelines on the issues of pollution (Salu, 1999). According to 
the Federal Environmental Protection Agency, Lagos Nigeria, the 
following relevant national laws and international agreements are 
in effect: 
a. Endangered Species Decree Cap 108 LEN 1990. 
b. Federal Environmental protection Agency Act Cap 131 
LFN 1990. 
c. . Harmful Waste Cap 165 LEN 1990. 
d. Petroleum (Drilling and Production) Regulations, 1969. 
e. Mineral Oil (Safety) Regulations, 1963. 
{. International Convention on the Establishment of an 
International Fund for Compensation for Oil Pollution 
Damage, 1971 
Convention on the Prevention of Marine pollution 
Damage, 1972 
h. African Convention on the Conservation of Nature and 
Natural Resources,1968 
i. International Convention on the Establishment of an 
International Fund for the Compensation for Oil 
Pollution Damage, 1971. 
References to Caps, volumes and pages are as in the laws of the 
Federation of Nigeria. Some of the acts and regulations on 
pollution given by (Oshineye, 2000) are given below: 
i The Mineral Oil (Safety) Regulations 1963, that deals 
with safe discharge of inflammable gases and provide 
penalties for contravention and non-compliance. 
ii. Petroleum Regulations 1967 that prohibit discharge or 
escape of petroleum into waters within harbour area and 
make provisions for precautions in the conveyance of 
petroleum and rules for safe operation of pipelines. 
iii. Petroleum Drilling and Production Regulation 1969 
that requires licence holders to take all practical 
precautions, including the provision of up-to-date 
equipment approved by the appropriate authority to 
prevent pollution of inland waters, river water courses, 
the territorial waters of Nigeria or the high seas by oil or 
other fluids or substances. 
iv. Oil in Navigable Waters Act 1968 that prohibits 
discharge of oil or any mixture containing oil into the 
territorial or navigable inland waters. 
v. Oil Terminal Dues Act 1969 that prohibits oil 
discharge to area of the continental shelf within which 
any oil terminal is situated. 
vi. Petroleum Refining Regulations 1974, which deals, 
among other things, with construction requirements for 
oil storage tanks to minimise damage from leakage. 
vii. Associated Gas Re-Injection Act 1979 that provides 
for the utilisation of gas produced in association with cil 
and for the re-injection of such associated gas rot 
utilised in an industrial project. This is to discour 
gas flaring. The Government has raised the penalty 
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