A multispectral remote sensing analysis of Danube Delta and North-Western coastal zone of Black Sea

Maria Zoran
National Institute of R&D for Optoelectronics, Remote Sensing Department, Bucharest, Romania
mzoran@inoe.inoe.ro

Liviu Florin Zoran
University Politechnica of Bucharest, Romania

ABSTRACT

The comprehensive knowledge of the physical and biogeochemical processes on the environmental state in the near-shore area for the Danube delta and the north-western coastal zone of the Black Sea represents an important aspect of integrated deltaic zone management.

The delta and marine coastal zone contains that unique environmental triple point where the water, land and atmospheric components of the terrestrial surface converge and interact. Special hydrodynamic regimes are produced by the mixing of fresh with salt water resulting in complex features of the coastal zone.

Remote sensing provides a means for locating, identifying and mapping certain coastal features and assessing spatio-temporal changes and their environmental impact. The Danube Delta wetlands and aquatic ecosystem, declared a Biosphere Reserve, are endangered by local, regional or global changes as a result of pollution, eutrophication, offshore activities, overexploiting of the resources. An environmental impact assessment was developed due to the urgent need for effective monitoring and management of these areas in response to their high disturbance levels. Multispectral and multitemporal satellite data ( LANDSAT MSS, TM , SPOT, MODIS, SAR –ERS, ASTER ) over some selected areas in the vicinity of the Danube mouths and north-western coastal zone of the Black Sea with highest nutrient concentration were analysed by comparing and mapping land cover change via change detection. Based on existing historical and more recent data the link was established between phytoplankton bloom development and related harmful phenomena (land use, fertilizer utilisation, waste water treatments).

Morphological coastal modifications were analysed, between 1975 and 2003, and also the sediment discharge and depositing regime in the Danube delta and surrounding sea area. An intensive erosion process is taking place over the Romanian littoral. The eroded zones extend over about 100 km, over 70 km of which are placed in an area including the Danube Delta. These processes are attributed to natural phenomena as well as to anthropogenic impact which contribute to a decrease of Danube River alluvial deposits and also disturb the natural sand circulation along the shoreline. As expected, nutrient concentrations have the highest values in the vicinity of the Danube mouths.

Future studies must consider : the integration of the hydrological and nutrient dynamic models to develop a more general application in predicting the effects of environmental change; the production of interpretative maps to enable the identification of key elements responsible for the changes; the development and integration of socio-economic evaluation of river marginal wetland functions; the development of more operational approaches to catchment management through the integration of the computer models, the GIS and satellite and LIDAR remote sensing data for the functional assessment procedures of the delta-marine environment.

Last Update: 2005-03-16