Remote Sensing of Marine Water Quality as a Component of ICZM: Case Studies in the Mediterranean Sea

Remote sensing of coastal zones has become increasingly common in both scientific research and environmental management applications. In particular, "ocean colour" techniques promise to develop into a major tool for the assessment of water quality. Surface optical properties can be used to study presence, nature and concentration of water constituents, runoff patterns and sediment dynamics, coastal plumes, filaments and eddies. Examples of the near-coastal features that can be surveyed are provided by imagery of the Mediterranean Sea, collected by the Seaviewing Wide Field-of-View Sensor (SeaWiFS). This basin has limited geographical size, but displays a variety of environmental and climatic conditions, and constitutes a unique scale model of the larger oceans. Its coastal areas, impacted by continental drainage or by exchanges with other water bodies, present special water quality problems, due to the inflow of dissolved and suspended materials. Where major rivers are present, the coastal zone appears to be permanently under the direct influence of their plumes, as in the case of the Po river outflow in the northern Adriatic Sea. The impact of river runoff can be enhanced by current patterns, as in the Strait of Otranto, in the southern Adriatic Sea. The Alboran Sea presents more examples of permanent features related to surface currents, coastal upwelling and vertical mixing. Short-lived episodes of coastal runoff can be entrained in eddy sequences, like that modulating the Algerian current eastward of the Alboran Sea, and then spread offshore. Coastal filaments may also be generated by wind-driven upwelling, as seen off southern Sicily. These bring high concentration of water constituents quite far from their origin, as illustrated by their impact on the Maltese shores. In the eastern basin, known for its oligotrophic character, large plumes originate from the Egyptian-Israeli-Lebanese coast. Turbulent diffusion downstream of the Nile delta, owing to the prevailing cyclonic circulation of the Levantine basin, generates eddies extending offshore and impacting the ecological balance of the region. These Mediterranean Sea case studies provide indications about the potential of exploiting satellite imagery at the regional scale, together with more traditional in situ information, for a truly integrated approach to coastal management.

BARALE Vittorio; 

2007-12-17

RESEARCH PUBLISHING

JRC34059

978-981-05-8948-6,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC34059,