Za utvrđivanje hidroloških prilika na ušću rijeke Jadro provedena su mjerenja slanosti i temperature u koritu rijeke u srpnju 2012. Ovim se mjerenjima potvrdilo da se radi o tzv. uslojenom riječnom ušću kod kojega slatka voda teče u površinskom tankom sloju iznad morske vode. Nadalje je provedena simulacija nestacionarnog uslojenog tečenja pomoću numeričkog modela za određena hidrološka stanja. Utvrđene su karakteristične vrijednosti vodostaja, protoka i pripadajućih dužina intruzije morske vode u korito rijeke, čime se dobio kvalitetan uvid u procese zaslanjivanja ušća rijeke Jadro..; For determination of hydraulic conditions in the Jadro river mouth, salinity and temperature measurements were carried out in the river bed in July 2012. These measurements confirmed that this was a “stratified” river mouth where fresh water flows above sea water in a thin surface layer. Additionally, a simulation of non-stationary stratified flow was carried out with a numerical model for certain hydrological states. The characteristic values of water level, flow and accompanying lengths of salt water intrusion in the river bed were determined, offering a good insight into the salinization processes in the Jadro river mouth.