The Utility of Morphometric Parameters Extracted from SAR Radar Images in the Monitoring of the Dynamics of the Danube Island System, Giurgiu-Călăraşi Sector, Romania

Abstract

The Danube islands system is continuously undergoing real degradations caused by natural and anthropogenic processes, thus causing a weakening of the biological potential and generating ecological and socio-economic imbalances. The lack of frequent data on the morphometric parameters of the islands in this region constitutes a major gap for monitoring, understanding and diagnosing the state of their evolution. The aim of this work is to show the importance of morphometric parameters extracted from SAR radar amplitude images in the monitoring of the dynamics of the Danube island system, along the Giurgiu-Călăraşi sector, at the frontier of Romania – Bulgaria. This study conducted by extraction of islands allowed us to detect and monitor the evolution of each island and sub-island, between 1995 and 2009, with great precision. The results obtained showed a displacement of the island system in the South-East direction with an average annual velocity of about 1 m/year and sediment accumulations with an average radius velocity estimated at 1.34 m/year during this period of 14 years. The increase of sediment accumulation during the studied period is due to river bank erosion and to the major floods produced in 2005 on the tributary rivers and especially those of 2006 on the Danube River.