LETNIK 17, št. 27 (december 1999) / VOLUME 17, No.27 (December 1999)          (full paper pdf)

Izvleček
Kot glavni cilj naloge je predstavljena nadgraditev tridimenzionalnega baroklinega matematičnega modela PCFLOW3D, z novima moduloma za račun transporta lebdečih plavin in živega srebra v morskem okolju. Model omogoča račun hidrodinamičnih količin zaradi vpliva vetra, plimovanja ter vtokov in iztokov ob upoštevanju gostotne stratifikacije, račun resuspendiranja sedimenta z dna, račun transporta in disperzije lebdečih plavin ter račun transporta in disperzije živega srebra v raztopljeni obliki in vezanega na delce plavin. Kot verifikacija sedimentacijskega modula je izvedena primerjava z rešitvami analitičnih enačb, meritev v laboratoriju in naravi ter rezultati sorodnega modela.
Zbrani in obdelani so podatki o temperaturnih in slanostnih razmerah ter vetru v Tržaškem zalivu, pretokih, količini lebdečih plavin in temperaturi Soče ter vsebnosti živega srebra v vodi, lebdečih plavinah, sedimentu in pornih vodah. Iz podatkov so izračunane povprečne sezonske vrednosti parametrov, ki skupaj z vložki krajšega trajanja bistveno vplivajo na transport živega srebra in predstavljajo vhodne podatke modela. Na podlagi teh podatkov je narejen scenarij za dolgotrajne simulacije, s katerim nadomestimo modeliranje s povprečnimi letnimi vrednostmi.
Opisana je kalibracija in verifikacija modela PCFLOW3D na treh primerih, pri čemer so uporabljeni podatki meritev in opazovanj iz let 1995, 1996 in 1997. Ugotovljeno je kvalitativno dobro ujemanje rezultatov modela z meritvami, kjer je mogoča kvantitativna primerjava, pa je ujemanje v okviru faktorja dve.

Ključne besede: matematični model, tridimenzionalni model, hidrodinamika, transport sedimentov, lebdeče plavine, resuspenzija, Tržaški zaliv, severni Jadran, živo srebro

UDK 532.5:546.49:556.535.6(262.3)

Abstract
An upgrade of the existing three-dimensional baroclinic mathematical model PCFLOW3D is presented. Two new modules were developed to simulate processes in aquatic environment. Resuspension of bottom sediment, transport and dispersion of suspended sediment and transport and dispersion of mercury in its dissolved and particulate form was included in the model. Hydrodynamics due to wind forcing, tidal forcing and river inflow momentum can be simulated, and stratified conditions can be taken into account. A comparison with solutions of analytical equations, laboratory and field measurements, and results of a similar sediment transport model was obtained to verify the sediment transport module.
A large amount of data about temperature and salinity fields in the Gulf of Trieste, wind conditions above the Gulf, Soča River discharges, suspended sediment concentrations and temperatures were collected and interpreted. The described data, together with measurements of the mercury concentrations in the water, suspended sediment, bottom sediment and pore waters in the Soča River and the Gulf of Trieste are used as input for the upgraded PCFLOW3D model. A scenario for long-term simulations on the basis of seasonally averaged parameters and values in a few shorter sequences was developed as a substitution for previous annually averaged simulations.
Measurements and observation data from the years 1995, 1996 and 1997 were applied to calibrate and verify the PCFLOW3D model. A good qualitative agreement of results and measurements was achieved. Whenever a quantitative comparison was possible, an accordance of measured and computed results within a factor of two is reached.

Key words: mathematical model, three-dimensional model, hydrodynamics, sediment transport, suspended sediment, resuspension, Gulf of Trieste, Northern Adriatic, mercury

UDC 532.5:546.49:556.535.6(262.3)