NEW DATA BASE OF THE GLACIAL LAKES IN THE ROMANIAN CARPATHIANS

Marcel Mindrescu, Andrei Zamosteanu, Ionuţ-Alexandru Cristea, University of Suceava, Romania

This study consists of a reevaluation of the database comprising all the glacial lakes located in the Romanian Carpathians, based on the information provided by Pişota (1968, 1971) and Mîndrescu (2006) and the data gathered from fieldwork and observations (mapping, measurements of lacustrine sediments thickness, primary analyses, etc.), as well as on the results obtained from processing of these primary sources of information by using GIS techniques (ArcView, Global Mapper, MapMaker).
Several sources were used in order to accurately identify and inventorize all the glacial lakes in the study area, including maps of the glacial lakes (Pişota, 1968, 1971), maps of glacial cirques for each glaciated massif (Mîndrescu, 2006), various individual studies of glacial lakes (Vespremeanu-Stroe, et. al., 2008), as well as topographic (scale 1:25.000, 1986) and geological (scale 1:200.000, 1968) maps and orthophotos (2005). By using GIS techniques, each glacial lake and its catchment have been digitized, thus obtaining geomorphometric data (e.g., area and perimeter of the lake and catchment, respectively, in 1986 and 2005, other parameters such as elevation, aspect, etc.). Additionally, all the bathymetric maps made by Pişota (1968, 1971) were re-digitized by using ArcView.
The final step was to generate maps of all the glacial lakes located in the Romanian Carpathians accompanied by a classification chart comprising elements such as name, code, coordinates, area and elevation of the lakes. For a better representation of the data obtained, maps were also drawn of each massif with its respective classified lakes. Moreover, two additional sets of maps were elaborated which focused on the geology of the lakes and their catchments accompanied by the afferent statistical data, and on the types of vegetation encountered within the catchments (forest, subalpine shrubs, grasslands).
The highest frequency of glacial lakes occurs between 1800-2200 m (approx. 85%), which leads to the conclusion that this altitude range has been the most intensely glaciated compared to the rest of the Romanian Carpathians. The analysis of the the geological data indicated that granitic substrates favored the formation of the highest number of lakes, which has also been documented in the central section of the Pyrenees (Garcia-Ruiz, et. al., 2000). Regarding the types of vegetation prevalent within the lake catchments, it has been established that roughly 70% of their area is covered by grassland, followed by shrubs (28%) and forested areas (2%).
To conclude, 161 glacial lakes were inventorized in the Romanian Carpathians, of which 154 are cirque lakes and the remaining 7 are valley lakes, as well as an additional 78 silted glacial lakes (peatbogs and shallow glacial lakes).

Keywords: glacial lakes, morphometry, data base, Carpathians