外文翻譯--對于石油泄漏的先進空間探測技術

1、<p>　　Advanced Space Technology for Oil Spill Detection</p><p>　　Maral H. Zeynalova, Rustam B. Rustamov and Saida E. Salahova</p><p>　　Abstract Environmental pollution, including oil spill

2、is one of the major ecological problems. Negative human impacts demands to develop appropriate legislations within the national and international framework for marine and coastal environment as well as the onshore protec

3、tion. Several seas, for instance the Mediterranean, the Baltic and the North Seas were declared as special areas where ship discharges are completely prohibited (Satellite Monitoring, LUKOIL).</p><p>　　In th

4、is regard environmental protection of the Caspian Sea has a priority status for Azerbaijan as a closed water basin ecosystem. This area, as a highly sensitive area in the World requires permanent ecological monitoring se

5、rvices where oil and gas from the subsurface of the Caspian Sea is developing almost more than a century. This status of the Caspian Sea is expected to be retention at least for the coming ?fty years.</p><p>

6、;　　Remote sensing is a key instrument for successful response to the onshore and offshore oil spills impacts. There is an extreme need for timely recognition of the oil spilled areas with the exact place of location, ext

7、ent of its oil contamination and veri?cation of predictions of the movement and fate of oil slicks.</p><p>　　Black Sea region is expected to have a dramatic increase in the traf?c of crude oil (mainly from t

8、he Caspian region). The main reason for these changes is the growth of oil industry in both Kazakhstan and Azerbaijan. The real substantial changes in tanker movements and routs are not clear till now.</p><p&g

9、t;　　A necessity for a continuous observation of the marine environment comes afore when clarifying the tendencies of changes in the concentration of the particularly dangerous polluting substances as well as the behavior

10、 of different kinds of polluting substances in the detected area i.e., creation of a system for monitoring the pollution (L.A. Stoyanov and G.D. Balashov, UNISPACE III, Varna, Bulgaria).</p><p>　　The explora

11、tion of geological and oil production started in the shelf of the Caspian Sea a long time ago. The Caspian Sea is a highly sensitive region on ecological and biodiversity point of view. Oil dumps and emergency oil spill

12、have an extremely bad in?uence on the marine and earth ecosystem and can lead to the ecological balance.</p><p>　　Certainly the general issue of oil and gas pipeline safety includes aspects of natural disast

13、ers and problems related to the environment. After successful construction of the Baku-Tbilisi-Ceyhan oil pipeline and Baku-Tbilisi-Erzrum gas pipeline these aspects especially became very important for Azerbaijan and de

14、?nitely, for the region. The Baku-Tbilisi-Ceyhan Crude Oil Export Pipeline comprises a regional crude oil export transportation system, approximately 1750 in overall length.</p><p>　　Generally, oil spill mon

15、itoring in the offshore and onshore is carried out by means of specially equipped airborne, ships and satellites. Obviously, daylights and weather conditions limit marine and aerial surveillance of oil spills.</p>

16、<p>　　Keywords Space technology. Space image. Oil spil Detection</p><p>　　Introduction</p><p>　　Generally, oil spillage is categorized into four groups: minor, medium, major and disaster

17、. Minor spill neither takes place when oil discharge is less than 25 barrels in inland waters nor less than 250 barrels on land, the offshore or coastal waters that does nor pose a threat to the public health or welfare.

18、 In case of the medium spill the spill must be 250 barrels or less in the inland water or from 250 to 2 500 barrels on land, offshore and coastal water while for the major spill, the dischar</p><p>　　Satelli

19、te-based remote sensing equipment installed in the satellite is used for monitoring, detecting and identifying sources of accidental oil spills. Remote sensing devices include the use of infrared, video and photography f

20、rom airborne platforms. In the mean time presently a number of systems like airborne radar, laser ?uorescence, microwave radiometer, SAR, ERS 1, ERS 2, ENVISAT and LANDSAT satellite systems are applied for the same purpo

21、ses. Currently more than a dozen satellites are in th</p><p>　　Spatial resolution of sensors ranges from 1 meter (e.g. IKONOS) to several kilo-meters (e.g. GEOS)</p><p>　　Satellite sensors commo

22、nly use visible to near-infrared, infrared and microwaveportions of electromagnetic spectrum;</p><p>　　Spectral resolution of satellite data ranges from single band (Radarsat) to multibands (e.g. MODIS with

23、36 bands)</p><p>　　Temporal resolution (repeat time) varies from several times a day (e.g. Meteosat)</p><p>　　The majority of satellites are sun synchronous and polar orbiting, crossing the equa

24、tor at around 10 a.m. local time during their descending pass</p><p>　　Digital data are available in both panchromatic (black and white) and multi- spectral modes</p><p>　　Using the recent advan

25、ced space technology, the following methodology can be applied for the oil spills detections:</p><p>　　Development of oil spill detection methods for the purpose of practical oil spill surveillance related t

26、o the space imagery with application of any weather conditions;</p><p>　　Adaptation of the observation to other systems to predict the oil spill spread direction and ?ow rate characteristics, determination t

27、he pollutant contaminations;</p><p>　　Development of appropriate data and user interface</p><p>　　There is a need for effectively direct spill countermeasures such as mechanical containment and

28、recovery, dispersant application and burning, protection of sites along threatened coastlines and the preparation of resources for the shoreline clean-up.</p><p>　　As it is mentioned in the beginning, the re

29、mote sensing is one of the main methods for an effective response to the oil spills environmental monitoring. Timely response to an oil spill requires rapid investigation of the spill site to determine its exact location

30、, extent of oil contamination, oil spill thickness, in particular.</p><p>　　Policy makers, managers, scientists and the public can view the changing environment using the satellite images. Remote sensing is

31、the discipline of observing the Earth’s surface without direct contact with the objects located at the surface. It allows obtaining information about the planet and human activities from a distance which can reveal inter

32、esting features that may not be possible or affordable from the ground level. One of the applications of remote sensing is water and coastal resource</p><p>　　Determination of surface water areas</p>

33、<p>　　Monitoring the environmental effects of human activities;</p><p>　　Mapping ?oods and ?ood plains;</p><p>　　Determination of the extent of snow and ice;</p><p>　　Measuring

34、 glacial features;</p><p>　　Mapping shoreline changes;</p><p>　　Tracing oil and pollutions.</p><p>　　The fact that remote sensing allows multi-temporal analysis is also very importa

35、nt. This means that an area of interest can be monitored over time so that changes can be detected. It allows analyzing phenomena like vegetation growth during different seasons, the extent of annual ?oods, the retreat o

36、f glaciers or the spread of forest ?res or oil spills (Vhenenye Okoro, 2004).</p><p>　　Remote sensing is a useful method in several modes of oil spill control, including a large scale area of surveillance ab

37、ility, speci?c site monitoring and advantages of technical and technological assistance in emergency cases. There is a signi?cant capacity of providing essential information to enhance strategic and tactical decision-mak

38、ing, decreasing response costs by facilitating rapid oil recovery and ultimately minimizing impacts.</p><p>　　Observation can be undertaken visually or by using remote sensing systems. In remote sensing, a s

39、ensor other than human vision or conventional photography is used to detect or map oil spills.</p><p>　　Oil Spill Detection</p><p>　　Oil production and transportation is started on the offshore

40、“Azeri – Chiraq – Guneshli” oil?eld, located at the Azerbaijani sector of the Caspian Sea. Therefore development and implementation of onshore and offshore oil spill monitoring and detection are highly important for the

41、Caspian Sea basin countries. Figure 1 shows the overall map of the Caspian Sea region countries.</p><p>　　Oil statistics of the major Caspian Sea oil producing countries are presented in Table 1.</p>

42、<p>　　For visual observations of oil spill from the air using the video photography are the simplest, most common and convenient method of determining the location and extent (scale and size) of an oil spill. There

43、are a number of sensors on surveillance of the sea surface:</p><p>　　Microwave radiometers which allow the determination of the oil thickness;</p><p>　　Ultraviolet and infrared scanners which al

44、low to detect respectively very thin and very thick oil ?lms;</p><p>　　Laser ?uorescence sensors which allow the determination of oil type.</p><p>　　Fig. 1 Overall map of the Caspian Sea region

45、countries</p><p>　　Application of remote sensing method for spilled oil can be discovered using a helicopter, particularly over near-shore waters where their ?exibility is an advantage along intricate coasti

46、ng with cliffs, coves and islands. For the spill response efforts to be focused on the most signi?cant areas of the spill, it is important to take into consideration relative and heaviest concentrations of oil. Geographi

47、cal positioning systems (GPS) or other available aircraft positioning systems creates a posi</p><p>　　In the open ocean spills show a less need for rapid changes in ?ying speed, direction and altitude, in th

48、ese instances the use of low altitude, ?xed-wing aircraft proved to be the most effective tactical method for obtaining information about spills and assisting in spill response.</p><p>　　Oil spill detection

49、is still performed mainly by visual observation which is limited to favorable sea and atmospheric conditions and any operation in rain, fog or darkness is eliminated. Visual observations are restricted to the registratio

50、n of the spill because there is no mechanism for positive oil detection. Very thin oil sheens are also dif?cult to detect especially in misty or other conditions that limit vision.Oil is dif?cult to discover in high seas

51、 and among debris or weeds where it can </p><p>　　Estimation of the quantity of oil observed at sea is the main issue for the detection of the oil spill. Observers are generally able to distinguish between s

52、heen and thicker patches of oil. However gauging the oil thickness and coverage is not always easy and it can be more dif?cult if the sea is rough. It is essential to view all such estimates with considerable caution.<

53、;/p><p>　　Purpose of the remote sensing equipment mounted in aircraft is increasingly used to monitor, detect and identify sources of illegal marine discharges and to monitor accidental oil spills. Remote sensi

54、ng devices except infrared video and photography from airborne platforms, thermal infrared imaging, airborne laser ?uourosensors, airborne and satellite optical sensors use satellite Synthetic Aperture Radar (SAR). Advan

55、tages of SAR sensors over optical ones is their ability to provide data in poor </p><p>　　A number of remote sensors placed on Earth observation satellites can also detect spilled oil as well. Optical observ

56、ation of spilled oil by the satellite requires clear skies, thereby limits the usefulness of such system. SAR is not restricted by the presence of cloud, thus it is a more useful tool. However with radar imagery, it is q

57、uite dif?cult to be certain if an anomalous feature on a satellite image is caused by the presence of oil. Consequently, radar imagery from SAR requires expert int</p><p>　　Oil Spill Monitoring and Data Deve

58、lopment</p><p>　　The Method of Oil Spill Monitoring</p><p>　　Due to the operation of the oil?eld “Azeri – Chirag – Guneshli” (ACG), located in the Azerbaijani sector of the Caspian Sea oil produ

59、ction was increased. From the beginning of 1997 development of ACG up to December, 1st, 2006 Azerbaijan International Operating Company (AIOC) could extract a crude oil from interior of the Caspian Sea already 81,25 mill

60、ion tons of oil where oil?eld “Chirag” produced 51,06 million tons.</p><p>　　The pipeline will extend the capacity and as a result of this it is a need of creating a reliable monitoring system for the more s

61、ensitive areas with the greatest oil spill risk.</p><p>　　Exploration work and oil production began on the Caspian Sea shelf a long time ago. The Caspian Sea is characterized by an extreme ecological sensiti

62、vity and a high biodiversity. Oil damps and emergency of oil spill are an extremely bad in?uence for the offshore and onshore ecosystems of Absheron peninsula and can lead to an ecological disturbance.</p><p&g

63、t;　　Aerial surveys of large areas of the sea to check the presence of oil spills are limited to daylight hours in good weather conditions. Satellite imagery can help greatly in identifying oil spills on water surface.<

64、;/p><p>　　The current challenge to remote sensing and GIS-based investigations is to combine data from the past and the present in order to predict the future. In the meantime it is likely that a long term or i

65、ntegrative study will combine remote sensing data from different sources. This requires a calibration between remote sensing technologies. Discrepancies in post-launch calibrations of certain remote sensing devices may c

66、ause artifacts such as surface area change, and so may the shift from one remote</p><p>　　Remote sensing plays an integral role in environmental assessment. Remote sensing will never replace the ?eld work an

67、d observations but it offers a great support in huge areas as follows:</p><p>　　Remote and dif?cult access areas like dense forests, glaciated areas, swamps, high elevation, etc;</p><p>　　Areas

68、undergoing rapid changes;</p><p>　　Countries with poor infrastructure and limited transportation;</p><p>　　Areas of active natural hazards and disasters: ?ooded areas, active volcanic regions, f

69、orest ?res, earthquake and landslide hazardous areas, etc;</p><p>　　Construction of a broad overview or a detailed map of a large area.</p><p>　　Remote sensing techniques can increase the speed

70、in which one can analyze a landscape and therefore help make quick and focused decisions.</p><p>　　Among the available remote sensing technologies producing high spatial resolution data, aerial photography w

71、as superior to space-borne data, despite the higher spectral resolution of the latter. However, digital air-borne multi-spectral imagery such as the Compact Air-Borne Spectrographic Imager (CASI) is at least as accurate

72、as aerial photography for the same purpose and it is less expensive to obtain and therefore more cost effective. It is also important to proceed in the evaluation of new sc</p><p>　　Required Parameters</p

73、><p>　　Spatial resolution requirements are various but it is necessary to consider even for massive oil spills. It is well known that spills at sea from windrows with widths are often less than 10 m. A spatial

74、resolution is greater than it is required to detect these spills. Furthermore, when considering oil spills, information is often required on a relatively short timescale to be useful to spill response personnel. The spat

75、ial and temporal requirements for oil spills depend on what use would be give</p><p>　　At present time such opportunities are available on board the European Space Agency’s ENVISAT (radar ASAR) and ERS-2 sat

76、ellites and the Canadian Space Agency’s RADARSAT satellite.</p><p>　　Oil spillage on the water surface forms oil sheen. When oil is forming a thin layer on the sea surface it will damp the capillary waves. D

77、ue to the difference in backscatter signals from the surface covered by oil and areas with the lack of oil, radar satellites may detect oil spill sheens at the sea surface. Oil spills on radar images can be characterized

78、 by following parameters:</p><p>　　form (oil pollution are characterized the simple geometrical form);</p><p>　　edges (smooth border with a greater gradient than oil sheen of natural origin);<

79、;/p><p>　　sizes (greater oil sheen usually are slicks of natural origins);</p><p>　　eographical location (mainly oil spills occur in oil production areas or ways of oil transportation).</p>

80、<p>　　Besides an oil spillage area scanning of sheen thickness allows to de?ne the quantity of the spilled oil. Depending on the temperature of water, properties of oil (viscosity, density) thickness of oil spill la

81、yer will be different. A critical gap in responding to oil spills is the present lack of capability to measure and accu- rately map the thickness of spilled oil on the water surface. There are no operational sensors, cur

82、rently available that provide absolute measurement of oil thickness on </p><p>　　Oil spills on the sea surface are detectable by imaging radars, because they damp the short surface waves that are responsible

83、 for the radar backscattering. The oil spills appear as a dark patches on radar images. However, natural surface ?lms often encountered in the coastal regions with biological activity also damp the short surface waves an

84、d 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 initializi</p><p>　　Figure 2 shows an example of oil spill of t

85、he Absheron peninsula oil spill taken by ENVISAT ASAR. This ?gure re?ects a necessity of the permanent monitoring of the Caspian Sea for more sensitive areas.</p><p>　　Fig. 2 ENVISAT ASAR image in the Caspia

86、n Sea near the Absheron peninsula for oil spill due to the offshore oil production</p><p>　　Underwater stream and wind transfers the oil placed on the sea surface. Oil moving speed makes approximately 60% fr

87、om the underwater stream speed and 2–4% from the wind speed (Sh. Gadimova, Thailand, 2002). The following demonstrates disadvantages of the radar satellite images:</p><p>　　in some cases signatures of oil sp

88、ill are dif?cult to distinguish a biogenic origin and other sea phenomena;</p><p>　　presence of wind have an essential in?uence on oil spill de?nition on the water surface.</p><p>　　At a gentle

89、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 identi?cation of pollution becomes impossible. The speed of wind between 3–11 m/s is a

90、 suf?cient suitable case for identi?cation of oil spills, slicks seem a dark on a light water surface. In the high speed of a wind oil spill identi?cation will be inconvenient as they disappear from images owing to mixin

91、g with the top layer of water.</p><p>　　For more optimum monitoring of sea oil spill is recommended to carry out the following:</p><p>　　(i) analysis of sea surface currents;</p><p>

92、;　　(ii) analysis of the information about the sea level, wave height and wind speed;</p><p>　　(iii) analysis of the meteorological information, allowing to estimate speed and direction of a spot.</p>

93、<p>　　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 ?elds and from industrial and municipal

94、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 f

95、ollow the surface currents are very likely wind-induced. The most remar</p><p>　　This is one more example of application of space technology for environmental monitoring of the sea surface.</p><p&

96、gt;　　Except foregoing mentioned areas, an application of satellite monitoring for pipelines can include below indicated problems as:</p><p>　　detection of oil/gas leaking;</p><p>　　no authorized

97、 intrusion into a safety zone of object;</p><p>　　detection of failures and an estimation of ecological damage;</p><p>　　detection and monitoring of pipelines moving (can be caused soil substanc

98、e).</p><p>　　Table 3 demonstrates the basic parameters of used equipment for oil spill monitoring</p><p>　　Remote Sensing Data Analysis</p><p>　　Investigation of the petroleum hydro

99、carbons on a plot and its analysis is advisable to conduct before and after the oil spill, to characterize changes in vegetative condition through time. Figure 4 shows an example of the oil spill accident occurred due to