Modeling and simulation of an italian ramsar site: the Comacchio lagoon

The geographical position of Comacchio Valleys and the low quality of their associated interconnection rivers contribute to the delicate ecological equilibrium of this vulnerable area. This fragility and unpredictability heavily conditions the area economy that takes advantage of the peculiar environment characteristics to exploit the potentialities of the fish harvest. Previous studies have analyzed the hypertrophic state of water and the instability of the lagoon ecosystem, confirming the difficult exchange with the sea and the high times of the inside waters turn over. Moreover they have underlined that these modest exchanges should, in any case, be considered only as theoretical, because large lagoon areas, in absence of particularly favorable meteorological conditions, are completely excluded from significant water exchanges. The improvement of the structure of the valleys is a problem so important, delicate and of such dimension to require the aid of an effective computational tool allowing the simulation of the evolution of the hydrodynamic, physical and chemical parameters (superficial water speed, dissolved oxygen in the column of water and in the interstitial water inside the sediments, production in sediments of hydrogen sulfide and its dispersion in the impending zones), consequent to different environmental conditions or to morphological changes due to the presence of man.