Degradation of the Azov Sea regional socio-ecological system.

METHODS



Archive data study

At the first stage we plan to study the archive data concerning:
  • pollution in Azov Sea region (for water, bottom sediments, invertebrates and fishes)
  • hypoxia and anoxia dynamics, salinity and nutrients distribution
  • zooplankton and predatory ctenophore Mnemiopsis leidyi distribution
  • fish larvae and adults fishes dynamics

The observation data is present at the Institutions listed below. The data elaboration will include the digitisation, recalculation in standard units, classification, and distribution between the project participants.

Mathematical modeling

Hydrophysical processes modeling

This model block goal is to study the propagation of admixtures including pollutants as a result of advection and turbulence. For the hydrophysical processes description the models, considering temporal and spatial variability of the turbulent exchange characteristics will be used. The diffusion task should be resolved together with hydrodynamics one, which should reflect the peculiarities of the currents and bottom relief and should be based on the 2D or 3D system of momentum equations. An equation of turbulence kinetic energy (k-epsilon assumption) should be used for diffusion parameterization.

Hydrochemical processes modeling

Mathematical modelling of anoxic conditions formation as result of anthropogenic eutrophication

The goal of this work was to parametrize biogeochemical processes of chemical elements cycling responsible for transformation of oxic conditions into anoxic.

The model computes concentrations of hydrogen sulphide, total elemental sulphur, thiosulphate (and sulphites), sulphate, total organic nitrogen, nitrates, nitrites ammonia, dissolved manganese, particulate manganese and dissolved oxygen. The processes of ammonification, nitrification, nitrate reduction (and denitrification), thiodenitrification and NH4 assimilation, H2S oxidation, sulphate reduction, manganese oxidation and reduction were described. Compound distributions were calculated on the base of one- and two-dimensional equations of diffusion with sources. The boundary conditions of 1 and 2 (Orlansky similarity) were used.

Model results confirm that the existence of reduced conditions is mainly controlled by the peculiarities of organic matter decay (consequence of oxidants consumption) accompanied by restricted aeration waters.. The model was calibrated using the observed data on the components vertical distribution in the Black Sea, Arabian Sea and oxic ocean.

The model allows to predict the appearance of hypoxic or anoxic conditions as result of eutrophication and pollution as well as dam construction.

Some results of this work are available via Internet in: http://fadr.msu.ru/mmc

Biological modelling

As the results of the hydrophysical and hydrochemical models the estimates of the possible spatial and temporal changes of biological parameters will be obtained. These estimates should be used for analysing the ecosystem changes.



Azov
Project
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