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Besides an oil spillage area scanning of sheen thickness allows to define the quantity of the spilled oil. Depending on the temperature of water, properties of oil (viscosity, density) thickness of oil spill layer will be different. A critical gap in responding to oil spills is the present lack of capability to measure and accurately map the thickness of spilled oil on the water surface. There are no operational sensors, currently available that provide absolute measurement of oil thickness on the surface of water. A thickness sensor would allow spill countermeasures to be effectively directed to the thickest portions of the oil slick. Some infrared sensors have the ability to measure relative oil thickness. Thick oil appears hotter than the surrounding water during daytime. Composite images of an oil slick in both ultraviolet and infrared sensors showed able to show relative thickness in various areas with the thicker portions mapped in infrared and the thin portions mapped in ultraviolet.

Oil spills on the sea surface are detectable by imaging radars, because they damp the short surface waves that are responsible for the radar backscattering. The oil spills appear as a dark patches on radar images. However, natural surface films often encountered in the coastal regions with biological activity also damp the short surface waves and thus also give rise to dark patches on radar images. Whereas, the shape can identify oil spills. Furthermore, remote sensing can be in use of initializing and validating models that describe the drift and dispersion of oil spills.

Figure 2 shows an example of oil spill of the Absheron peninsula oil spill taken by ENVISAT ASAR. This figure reflects a necessity of the permanent monitoring of the Caspian Sea for more sensitive areas.

Fig. 2 ENVISAT ASAR image in the Caspian Sea near the Absheron peninsula for oil spill due to the offshore oil production

Fig. 2 ENVISAT ASAR image in the Caspian Sea near the Absheron peninsula for oil spill due to the offshore oil production

Radar Oil Spill Caspian Sea

Underwater stream and wind transfers the oil placed on the sea surface. Oil moving speed makes approximately 60% from the underwater stream speed and 2-4% from the wind speed (Sh. Gadimova, Thailand, 2002).

The following demonstrates disadvantages of the radar satellite images:

- in some cases signatures of oil spill are difficult to distinguish a biogenic origin and other sea phenomena;

- presence of wind have an essential influence on oil spill definition on the water surface.

At a gentle breeze (0-3.0 m/s), the water surface looks dark on radar images. In this case oil sheens merge with a dark background of the sea and identification of pollution becomes impossible. The speed of wind between 3-11 m/s is a sufficient suitable case for identification of oil spills, slicks seem a dark on a light water surface. In the high speed of a wind oil spill identification will be inconvenient as they disappear from images owing to mixing with the top layer of water.

For more optimum monitoring of sea oil spill is recommended to carry out the following:

(i) analysis of sea surface currents;

(ii) analysis of the information about the sea level, wave height and wind speed;

(iii) analysis of the meteorological information, allowing to estimate speed and direction of a spot.

Figure 3 shows southern of the Caspian Sea at the Volga estuary. This river carries a heavy load of pollutants originating from fertilizers washed out from agricultural fields and from industrial and municipal plants. They serve as nutrients for the marine organisms which experience a rapid growth and then generate biogenic surface slicks. The oceanic eddies which become visible on the radar images because the surface slicks follow the surface currents are very likely wind-induced. The most remarkable feature on this image is the mushroom-like feature consisting of two counter-rotating eddies.

This is one more example of application of space technology for environmental monitoring of the sea surface.

Except foregoing mentioned areas, an application of satellite monitoring for pipelines can include below indicated problems as:

• detection of oil/gas leaking;

• no authorized intrusion into a safety zone of object;

• detection of failures and an estimation of ecological damage;

• detection and monitoring of pipelines moving (can be caused soil substance).

Table 3 demonstrates the basic parameters of used equipment for oil spill monitoring.

Fig. 3 Southern of the Caspian Sea at the Volga estuary (ERS-2 image acquired 12 October 1993 imaged area: 100 km x 100 km)

Fig. 3 Southern of the Caspian Sea at the Volga estuary (ERS-2 image acquired 12 October 1993 imaged area: 100 km x 100 km)

Table 3 The basic parameters of used equipment

Title

Satellite

Number of spectral wavelength, ^m

Spatial resolution, m

Swath, km

Shooting repetition

MODIS Terra Aqua

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Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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