Bottom intrusions of brackish water from the Vistula Lagoon into the Downstream Pregolya Branch

For the first time, the analysis (related to hydrometeorological conditions) of the temporal variability of vertical stratification, and the relationship between surge-induced and intrusive mechanisms of brackish water upstream penetration from the Vistula Lagoon into the Downstream Pregolya Branch. A quantitative assessment of the penetration depth of brackish water was made according to the Keulegan technique. Using the data of hydrological measurements for the period September 10, 2019 – March 27, 2020 and the features of the geomorphology of the riverbed, the possibility of the penetration of brackish water upstream the Downstream Pregolya Branch up to the bifurcation point of the Pregolya River with subsequent overflow into the Deyma Branch was estimated.