Abstract

The lack of an explicit methodology for the assessment of synergistic environmental impacts, highlight the need for more complete understanding of the phenomenon by means of a proper theory, proposed as a conceptual-systemic theory. This theory is obtained through two explanatory processes, generalization and causal explanation, to answer what is synergy and how does it work. Within the development of explanations a succession of models is built as an approximation to the real phenomenon, culminating in a functional translucent box model. The theory presents the phenomenon of environmental impact synergy as a scenario of system destabilization that allows the generation of greater effects than the predicted by the isolated impacts. The scenario is described by the coincidence of the (a) impacts, effects and disturbances, acting upon a specific tendency to describe a menace, (b) the system stability, specific for the tendency, constituting a vulnerability, as the (c) influence that the spatial context; between tendencies, watershed and landscape; and the temporal context; by the direct climatic variations y indirect through the influence of adjacent aquatic ecosystems. The synergy risk scenario may be described by the model through the Impact Bayesian Networks to analyze the menace, the Multicriteria Matrix to analyze vulnerability, and the construction of the spatial and temporal context to pose the scenarios, that along with the guidelines established by the theory may set the basis for a suitable impact synergy assessment.