ABSTRACT.- Seasonal discharge regime of the rivers in the Transylvanian Subcarpathians and the adjacent mountainous space between Târnava Mare and Niraj. The studied region is situated in the North-East of the Transylvanian Depression and includes two distinct units: the Transylvanian Subcarpathians and the Moldavo-Transylvanian Carpathians, comprised between the valleys of Târnava Mare and Niraj. The study is based upon the processing and interpretation of data coming from 13 hydrometric stations. In order to emphasize the particuliarities of the seasonal discharge regime, we took into account three periods (1950-1967, 1950-2009 and 1970-2009). The characteristics of the geographic coating from the studied area, especially the climatic and geomorphic ones, are clearly reflected in the discharge regime of river waters. Thus, on all rivers, spring discharge is predominant, and winter and autumn are the seasons with the lowest weight of the multiannual average volume. We have underlined the particuliarities of the three subtypes of seasonal regime and we have defined the limits of the corresponding display areas. The variation of the seasonal discharge on a multiannual level was outlined with the help of variation coefficients. Likewise, we also determined the discharge tendencies for the three studied intervals. The analysis carried out has revealed the fact that the rhythmic structure of the hydric system reflects the local characteristics of the supplying sources, of geological, as well as morphological and morphometrical conditions of the relief.

Keywords: regime, seasonal, monthly, type, subtype, Transylvanian Subcarpathians, Moldavo-Transylvanian Carpathians