Research conducted in the Preajba Valley catchment aimed they introduction on the list of protected nature reserves from our country.  Studies in this area were made by Brezeanu Gh, 2003, Cioboiu Olivia, 2002, Pleniceanu V., 2004. Preajba Valley catchment is characterized by a special contribution of groundwater quartered in alluvial deposits of the three levels of terraces from the left of Jiu River. Lakes formed by crossing the river Valea Preajba and its tributary Valea Bătrână, fragmenting them into 14 segments - areas that have formed as many lakes. It is noted that areas of lakes increases from upstream to downstream, fact correlated with their depths. The direction of this catchment is East-West, contrary to other of the Plain of Oltenia.  Preajba Basin is highlighted by ecological features of the area. Thus, in an area not exceeding 30 square kilometers are grouped a variety of continentalaquatic ecosystems: springs, streams, rivers, lakes and swamps. Each of these confer own features to biocenosis, plant and animal populations, this providing an image of ecological diversity in a limited geographical range. The study focused on determining the physicochemical parameters from the aquifer, related with the ecosystems biocenosis by which is populated. To determine the physicochemical properties of water were sampled from a variety of locations in order to establish exactly the character of each type of ecosystem and their combination: limnocrene, reocrene, limnoreocrene. This qualification explained largely physicochemical features of each category.  The spring water fits in 1-st quality category being exploited in order to supply the Craiova city. The water chemistry shows a high nitrates and phosphates content, being classified in eutrophic waters category. In terms of anion and cation content lakes could be described like bicarbonate sulphate calcic magnesic category, characteristics of mixed mineralization (is notice a high biogenic elements this being a particular character of the lakes). The waters fit in the 2-nd quality category, being used for fish (except salmon culture) as well as tourist and recreational purposes. The originality of the work lies in the classification of hydrological configurations and usage delimitation. The present study, beside to future environmental studies indicate this ecosystem as a new protected area.

ecosystem; protected area; hydrobiology; hydrochemistry; saprobiology

Presentation: oral