The present study analyzes the spatial temporal variation of maximum flow in Slănic Teleajen and Prahova river basins (upper basin). Maximum flow rates were analyzed in relation to the threshold values corresponding to the Defence Levels respectively the maximum flow which determines exceeding Warning and Flooding Levels. The series of major floods events, selected on the basis of the threshold values mentioned above, were then statistically analyzed to determine trends (Mann-Kendall test) and the variations in the level of frequency, analysis which was applied seasonally and annually. The analysis made revealed that trends in terms of maximum flow rates in the Prahova upper basin were generally negative (decreasing), statistically significant for the February, May, July, August and the annual average, while in Slanic river basin, the trend was mostly positive, statistically significant for October.

This paper concentrates information on the flash flood produced during 02-04.06.2016 in the Trotuş River basin. Maximum flows have been analyzed by reference to the thresholds corresponding to the Defense Levels. In order to show in a suggestive way the amplitude of the event, the characteristics of the flood were highlighted as well as a series of morphometric and hydrological data on the maximum flow of the Trotuș River. The hydrometric stations in the basin area, to which reference was made, were: Lunca de Sus, Goioasa, Tg. Ocna, Onești and Vrânceni. The flow series were represented graphically to be able to easily observe the evolution of the flood over time. The analysis showed that the flood produced on the Trotuș River had a great magnitude causing significant damages.