Pollution

The oil pollution of Gulf of Lion in the NW Mediterranean has been studied with SAR images during the period 1999 -2005. We have analyzed these SAR images with respect to other surface features such as wind, river plumes, eddies and convergence areas. Some results of our statistical analysis are presented showing that the NW Mediterranean is most polluted along the main ship traffic routes, but comparatively less that near other routes in the Indic and the Pacific. The oils spill index is higher than one. The sizes of the detected oil spills vary over a large range, and if the statistics of the largest accidents are also considered on a longer timescale, we show that Zipf's Law, relating the frequency and the size of the spill in a hyperbolic fashion is applicable. Advanced image analysis techniques, such as the calculation of the multi-fractal dimensions of the observed SAR signatures, have been applied to distinguish between natural slicks and antropogenic spills…

The region of the Gulf of Lions at the northwestern Mediterranean Sea has been studied within a two-year period from December 1996 until November 1998. More than 250 synthetic aperture radar (SAR) images, which have been acquired by the Second European Remote Sensing Satellite (ERS 1/2). In this paper, we present some results of the statistical analyses of several features revealed by SAR such as eddies and oil slicks dynamic features.Within the project "Clean Seas", which is funded by the European Commission, three test areas in European marginal waters, the southern Baltic Sea and North Sea and the northwestern Mediterranean were chosen for a comparative investigation of the remote sensing of marine pollution and other types of marine and atmospheric phenomena.Since natural (caused by plankton, fish, etc.) and man-made oil slicks dampen the small-scale surface waves, which are responsible for the radar backscattering from the water surface, they are visible…

In June 2003 LUKOIL-Kaliningradmorneft initiated a pilot project, aimed to the complex monitoring of the southeastern Baltic Sea, in connection with a beginning of oil production at continental shelf of Russia in March 2004. Operational monitoring was performed in June 2004 – November 2005 on the base of daily satellite remote sensing (AVHRR NOAA, MODIS, TOPEX/Poseidon, Jason-1, ENVISAT ASAR and RADARSAT SAR imagery) of sea surface temperature (SST), sea level, chlorophyll concentration, mesoscale dynamics, wind and waves, and oil spills. As a result complex information on oil pollution of thesea, SST, distribution of suspended matter, chlorophyll concentration, sea currents and meteorological parameters has been received. In total, 274 oil spills were detected in 230 ASAR ENVISAT images (400x400km, 75 m/pixel resolution) and 17 SAR RADARSAT images (300x300 km, 25 m/pixel resolution) received during 18 months. The interactive numerical model Seatrack Web SMHI (The Swedish…

This paper presents the state of the art for oil spill detection in the world oceans. We discuss different satellite sensors and oil spill detectability under varying conditions. In particular, we concentrate on the use of manual and automatic approaches to discriminate between oil slicks and look-alikes based on pattern recognition. We conclude with a discussion of suggestions for further research with respect to oilspill detection systems.

The location of the 2006 nuclear explosion in North Korea has been accurately imaged by back-projected regional Pn waves recorded by the Japanese Hi-net array. Based on the determined location, the nuclear explosion site can be identified from geo-referenced FORMOSAT-2 satellite images. The seismically determined epicenter is about 2.5km northeast of the original estimate of its absolute location. Results indicate that a remote suspect event had been unambiguously detected and accurately located by a dense array within a regional distance. Employing ground truth correction, the satellite images can be referenced forshifting the array-determined epicenter to its absolute position. After correction, this event can be treated as a reference event for accurately locating future nuclear explosions. Our study utilizes public information from a dense seismic network and further demonstrates that commercial observation satellites can accurately monitor compliance with the Comprehensive…

Satellite image data were used to detect, monitor and map different pollutants at five study sites along the El-Gamil beach, including El-Debba, El-Manasra, El-Fardousand El-Gamil inlets and the El-Gamil airport. The images were rectified and analysed by ERDAS IMAGINE 8.7. Image processing techniques were applied using ENVI 4.2 to analyse the SPOT image data (10 m resolution) for 2006. Image enhancement, principal component analysis (PCA), band ratios and supervised/unsupervised classifications were applied. Surface water samples were collected during the winter of 2005 and the summer of 2006. Water contamination was found to be higher in the summer than in the winter. SPOT image data from the summer, therefore, was selected to verify the results of metal analysis. Different pollutants detected along the El Manasra and El Debba sites are associated with industrial development, and discharge from natural gas companies and electric power generating stations. Significant water…

Stormwater runoff plumes, municipal wastewater plumes, and natural hydrocarbon seeps are important pollution hazards for the heavily populated Southern California Bight (SCB). Due to their small size, dynamic and episodic nature, these hazards are difficult to sample adequately using traditional in situ oceanographic methods. Complex coastal circulation and persistent cloud cover can further complicate detection and monitoring of these hazards. We use imagery from space-borne synthetic aperture radar (SAR), complemented by field measurements, to examine these hazards in the SCB. The hazards are detectable in SAR imagery because they deposit surfactants on the sea surface, smoothing capillary and small gravity waves to produce areas of reduced backscatter compared with the surrounding ocean. We suggest that high-resolution SAR, which obtains useful data regardless of darkness or cloud cover, could be an important observational tool for assessment and monitoring of coastal marine…

The paper discusses sea oil pollution detection, statistics and mapping in the Arabian Gulf waters, offshore the United Arab Emirates by using multi-satellite data with particular focus on SAR data from different platforms. The work is roughly divided into four main steps. Possible oil slicks are first identified from each image. Next, the slick is analyzed to separate natural slicks from possible oil spills. The later are subjected to further re-examination so that all possible oil spills are identified and mapped. The overall statistical results are then complied and percentages of occurrences of each spill type are calculated. Finally, spatial oil spill distribution maps in the Arabian Gulf waters; offshore the United Arab Emirates are derived and compiled in an “oil atlas”. The results show very good agreement with shipping routes, ships anchoring areas and oil production facilities.

A spatial distribution map of ocean oil pollution in the Southeast Asian waters has been compiled after analysing 2530 intermediate resolution ERA SAR quicklook images. The relative frequency of oil spills is characterised by a normalised oil spill index representing the average number of oil slicks detected in an ERS scene. Most oil spills are found along the major international shipping routes in this region as well as in those areas with intensive large-scale oil exploitation activities. This is probably the first time that thousands of satellite images have been used to derive spatial oil spill distribution statistics over a very large ocean area. The results will help in locating potentially vulnerable areas, and serve as a reference in future ocean oil spill monitoring campaigns.

On April 15 and 19, 1998, two intense dust storms were generated over the Gobi desert by springtime low-pressure systems descending from the northwest. The windblown dust was detected and its evolution followed by its yellow color on SeaWiFS satellite images, routine surface-based monitoring, and through serendipitous observations.The April 15 dust cloud was recirculating, and it was removed by a precipitating weathersystem over east Asia. The April 19 dust cloud crossed the Pacific Ocean in 5 days, subsided to the surface along the mountain ranges between British Columbia and California, and impacted severely the optical and the concentration environments of the region. In east Asia the dust clouds increased the albedo over the cloudless ocean andland by up to 10–20%, but it reduced the near-UV cloud reflectance, causing a yellow coloration of all surfaces. The yellow colored backscattering by the dust eludes a plausible explanation using simple Mie theory with…