ABSTRACT .- At the beginning there is given the definitions for hazard and risk concepts and a enumeration of the criteria for the hazards classification and for their purpose. Based on the utilized criteria number, there have been realized uni criterial and multicriterial classifications. The unicriterial classification of hydrological hazards used the next criteria: spatial, temporal, ways of manifestation, phenomenon nature, the generated impact, the effects perception and mitigation. In the second part of the study, based on numerous criteria, there is made a distinction between hydrological hazard from continents (extreme, hydrodynamic, stationary, of hydric interference, of physical, chemical, mechanical and mixed nature) and from the marine and oceanic environment (of dynamical, mechanical, physical and chemical nature).
Keywords: hydrological hazards, classification, criteria, continental area, marine and oceanic area.