# Graph formalization and multifactor analysis of environmental problems on example of the Caspian Sea.

The complex interactions between the processes of disturbed ecosystems are
often difficult to predict. The classical dynamic model may include a limited number of factors,
which act on the population balance just directly. In the common case of the transition to a
chaotic regime of discrete models are limited in predictive capabilities. Graph scheme allows
us to structure the information on the relationship between the factors in the subject field of
ecology terms. To continue the previous studies, we used the expanded view of the graph model
in the form of cognitive signed digraph. It was formalized information about the functioning
of the biotic components of the ecosystem of the Caspian Sea when the external influences.
These effects are set with four types of graph arcs to influence the situation mid 1980’s. In
those years, the optimal relied share $h = 3/5$ catch sturgeon spawning stock and conducted
a large-scale release of hatchery fish in the amount of millions young fish. On the basis of
comparison with the collapse of cod stocks in Canada is justified that the existing methods for
determining the commercial forecasts optimal exploitation strategy in fact lead to the depletion
of biological resources. Comparative analysis allows to discuss a real alternative measures to
prevent the degradation of biological resources. As the experience of similar cases, the collapse
of the Atlantic cod and Pacific herring Canada, control measuring withdrawal of fish to explore
and model calculations known models are ineffective. Indicators of the real fishing mortality
is systematically reduced, which acknowledged by R. Myers, and experts can not predict the
imminent collapse of stocks. Conclusions of fisheries management seem paradoxical. Is promising
variant a conscious rejection of the evaluation quantities the fishing stock. Conducting accounting
trawl Caspian sturgeon populations filled the minds of millions of fish and the ephemeral whetted
the appetites of fishers. Control over the observance of fishing rules is difficult, therefore the
catches are systematically underestimated. In reports erroneous data about the actual loss of
fish, in turn, affects the forecasting recovery of fish stocks.
Keywords: Cognitive graphs, ecological processes, weakly formalized area of knowledge structural
and dynamic simulation

UDC:
519.688, 573.7