Distribution of oil spills in inland seas based on SAR image analysis: a comparison between the Black Sea and the Caspian Sea

This article presents the results of routine satellite oil spill monitoring in the Eastern Black Sea (2011-2013) and the Northern & Middle Caspian Sea (2009-2013) by analysing synthetic aperture radar (SAR) images acquired by space-borne SARs on board the European Environmental Satellite, Canadian SAR-equipped Radarsat-1, and Radarsat-2. The focus of operational monitoring is to provide information that assists in adequate responses, as well as further investigates the problem of recent oil pollution in these seas. A number of state-of-the-art technologies developed by Research and Development Centre SCANEX have been used to address this problem. For example, GeoMixer allows the integration and combination of all information needed for analysis by integrating all detected and verified spills and combining annual oil spill distribution maps and comparing them. Distributions of oil spills in the Black Sea and in the Caspian Sea are quite different, i.e. in their spatial patterns. In the Black Sea, the most important source of oil pollution is tank washing in the open sea (producing spills of 20-100 km(2) or more) and illegal discharges. In the Caspian Sea, most of the detected oil spills in the northern and middle sections are from small ship-made discharges (<= 10 km(2)) related to cargo traffic and fisheries. Despite the oil exploration and production (LUKOIL and others) in the Northern Caspian, no oil spills related to oil production have been detected. An ill-estimated source is natural oil seeping, mainly in the southern part of the Caspian. It is therefore concluded that the distribution of oil spills in a particular sea may depend strongly on a number of causes, including ship and tanker traffic.