HYDROGEOLOGICAL CHARACTERISATION OF THE GROUNDWATER BODIES FROM THE SOUTHERN PART OF ROMANIA

For our Institution, the research undertaken in the "DANUBE WATER" project, had two main targets: the conditions of the surface waters including their perennial resources and the complex characterization of groundwater water bodies, respectively. In the southern part of Romania, by the processing of the hydro-stratigraphical data derivative from the drilling programmes for oil, coal and potable water, our team outlined the presence of the phreatic aquifers (water table) and of confined aquifers (having ascending or artesian level). These represent the official groundwater bodies, their identification and delimitation being done according to the Water Framework Directive 2000/60/EC. The criteria that were taken like the basis for identification and delimitation of groundwater bodies are: geological (petrography, age of formations that permit flow of meteoric water a.o) and hydrogeological (hydrodynamic characteristics, hydrogeological parameters a.o). Based on these criteria, in the southern part of the great Hydrogeological Dacic Basin were delimited eleven bodies of phreatic groundwater (from west to east ROJI06, ROJI05, ROOTS, ROOT09, ROAG09, ROAG10, ROAG07, ROAG05, ROIL11, ROIL17 and RODL10) and three deep groundwater bodies (from west to east ROJI07, RODL06 and RODL04). The phreatic groundwater bodies are located mainly in the Quaternary alluvial layers pertaining to the floodplain and to five terraces built by the Danube and its main tributaries: Jiu, Olt, Vedea, Arges rivers. From sedimentary petrography point of view, the alluvial extended beds consist of sands of various grain-size with gravel and boulders, locally with insertions of silt or clay. The thick layers of Danube terraces (having till 25 m thickness of coarser deposit) are overlain by the Aeolian Formation (5-to-20 m thick of fingering lenses of loess, loess-like, red clays, buried soils a. o), one excellent protector against the pollution. One main characteristic of the groundwater bodies hosted in the deposits of terraces is that their charge is downloading through the continuous lines of springs (cumulated yield is around of 1.5 L/s yield). These springs occur at the morphological contact from the terraces t(3), t(2) and t(1), respectively, to the main meadows. The well-known discharging lines are situated between Cetate and Calafat, Calarasi and Dabuleni, Potelu and Celei, Lita and Turnu Magurele localities). Confined groundwater bodies are located in the porous permeable layers of Lower Pliocene (Dacian in age) deposits well-developed in the western half of the Moesian Platform (massive pile of sands having <= 120 m thickness), in the Sarmatian sandstones and limestones (in central part of the Moesian Platform) and in the multi-layered aquifer (of Sarmatian biogenic limestone pile overlying the fissured-karstified sequence of Upper Jurassic- Lower Cretaceous in age, large extended in the eastern half of Moesian Platform (including the Southern Dobrogea uplifted panel).