A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1998

Accidents of oil tankers are spectacular and a local disaster for the marine environment but globally four times more oil is discharged from merchant ships during normal operation into the sea than from such tanker accidents. One possible way to detect illegal oil spillage of monitor oil pollution of the marine environment is to employ radar remote sensing techniques. For the period of September 1995 until June 1998, a number of 1544 ERS-1, ERS-2 and RADARSAT SAR quick-look images were analysed with aim of detecting oil spills in the part of the Southeast Asian waters. Furthermore, two full-resolution images for April 1996 and May 1996 were used for this study. A short assessment of the oil spill occurrences in Strait of Malacca, Gulf of Thailand and Brunei Bay, based on the interpretation of the low-resolution images, was done. The results indicate that oil spills, attributed to leakage or tank washing discharges, which usually escape detection and response,· comprise a considerable threat in the Southeast Asian waters centred upon Singapore. Moreover it appears, that certain regions are exposed to chronic pollution, calling for more focused detection. Two high-resolution images from selected targets allowed the errors to be classified. However, in order to discriminate between oil spills and natural sea surface slicks additional information to the radar contrast in SAR images is needed.