ALTERATION OF THE MORPHO-HYDROLOGICAL CONDITIONS OF THE AQUATIC COMPLEXES ADJACENT TO THE SF. GHEORGHE BRANCH (DANUBE DELTA) AS A RESULT OF THE HYDROTECHNICAL WORKS

Abstract

The hydrotechnical works on Sf. Gheorghe arm in Danube Delta was done by Institute for Research and Planning for Water Management. The work was part of the framework scheme for the Dobrogea hydrographic area and was nominated in the investment plan of the National Water Council. The regularization works, started in 1988, consists in the rectification of the main meanders of the arm in the following sectors: lvancea, Dranov, Dunavăț and Murighiol. The total length of the rectification is 15 km and the shortening of the natural course is 32 km. These works impose changes in the balance of the hydrological regime on the main course, along the meanders and on the channels connecting the arm waters and the aquatic complexes within the delta. By altering the fractal dimension of the arm, fluviatile processes are intensified and have irremediable long-term repercussions. This leads to the eutrophication of lakes in the aquatic complexes by low water intake, then clogging of the channels and, also, of the lakes resulting in diminishing / changing the habitats. As clear evidence are these two channels: Ivancea and Erenciuc north (completely clogged). Now, other 4 channels are threatened, which already show very low depths at the confluence with the Sf. Gheorghe arm. This is an exhaustive study of the current situation of the meanders of the Sf. Gheorghe arm from the morphological point of view and the fragile longitudinal and lateral connectivity through morphometric analysis methods using geomatics techniques. The foundation of this study will be based on existing literature, field data, historical and current data, in collaboration with other institutes and universities capable of providing important data such as sediments, hydro-technical works, etc.

Keywords

• danube delta
• wetlands
• geomatics
• underwater morphology