Maps of the topography of water surface levels in the Danube Delta, between the main branches

Abstract

Within the project “Hydrological Monitoring of Wetland Areas Using SAR Techniques (Hydro-SAR)”, concluded by the TERRASIGNA (Romania) with the European Space Agency (ESA), the task of GeoEcoMar was to track and check the correlation of data provided by InSAR techniques with ground observations and measurements in the Danube Delta. Activities in the field and laboratory enabled elaboration of maps of vector fields for the water flow directions on the Danube Delta territory, based on the relief of the water surface levels at 450, 400, 350, 300, 250, 200, 150, 100, 50 and 0 cm, measured at Tulcea hydrologic station. In order to elaborate the maps of water surface levels, the altimetric stability of hydrometric gauges from the Danube Delta territorry was checked by establishing the Earth crust subsidence in each gauge location. Interpretation of recorded data shows a relative low subsidence rate for the location of the hydrometric gauge in Tulcea (observations recorded for the period 1858-2013) selected as hydrometric reference point, with the origin of the zero of the gauge situated at 0.57 m altitude relative to the Black Sea – Sulina reference system. The paper presents isoline maps of the water surface levels on the surface of the Danube Delta between the main distributaries (Chilia – Sulina – Sf. Gheorghe), for the above mentioned water surface levels.

Keywords

• InSAR techniques
• water surface level
• hydrometric gauge
• empirical function