Geographical systems at risk. Taking into account the narrow manner in which terms such as “hazards”, “risks”, “disasters” etc. are traditionally defined, one of the goals of the study is to argue the necessity to interpret these concepts within the frame of the systems approach. Complexity is the basic property which allows the deep understanding of the role of those attributes that diversificate and radicalize the system’s behavior: the structural, relational and functional variability, the incertitude and the nonlinear processes that occurs in the system’s dynamics. Hazards, risks and disasters are considered as states or phenomena which have a strongly physical objective support and therefore to reduce their interpretation exclusively to their social dimensions represent an idealization which increase the confusion and misunderstanding of their real meanings. As a consequence confusions between concepts and inadequate message and utility are often observed. Therefore another aim of the present study was to interpret the dynamics of the geographical systems using the recent concepts and scientific theories which describe the nonlinear events such as: the theory of Dissipative Systems, Catastrophe theory and bifurcation, Chaos and turbulence theory etc. Finally geographical equivalencies were found to argue the hazardous deterministic behavior of the geosystems and possibilities to describe with accuracy the abrupt changes induced by risks were also explored