Modelling dataset on the Vistula Lagoon river runoff to assess the input of suspended matter, nutrients and pollutants into the South-East Baltic

The Vistula Lagoon is located in the south-eastern part of the Baltic Sea and is the second largest lagoon in the Baltic. Its transboundary (between Russia, Poland and Lithuania) catchment area is 21 ths. km2 [Chubarenko et al., 2017].The main river of the lagoon is the Pregolya River. The river is formed by the confluence of the Instruch River (right component) and the Węgorapa-Angrapa River together with its tributary the Pissa River (left component). The catchment area of ​​the Pregolya River (together with its main tributary, the Łyna-Lava River) is 13.7 ths. km2, its upper part (61%) is located in Poland, the lower part (39%) is in Russia (Kaliningrad Oblast), and less than 1% is in Lithuania. The average annual river discharge is 86 m3/s. The branch of the Pregolya River – the Deyma River – discharges about 40% of the runoff from the Pregolya River catchment into the Curonian Lagoon [Domnin et al., 2018]. In addition to the Pregolya River, the following rivers flow into the Vistula Lagoon (from north to south, clockwise): Primorskaya, Nelma, Prokhladnaya,Banówka-Mamonovka, Pasłęka, Bauda, Elbląg, Nogat, Szkarpawa.Not all of these rivers have hydrological data on water discharge. Therefore, in order to carry out assessments related to the calculation of the water balance of the Vistula Lagoon, the analysis of the input of suspended matter, nutrients and pollutants into the South-East Baltic [Chubarenko et al., 2024], model calculations of the water runoff from each river catchment were made.The modelling of water discharge entering the lagoon from the river catchments was carried out using the numerical model HYPE (HYdrological Predictions for the Environment), developed by the Swedish Meteo and Hydrological Institute (SMHI) [Source: https://hypeweb.smhi.se/model-water/about-hype-code]. The model calculates the time course of water runoff in the closing sections of the sub-basins, taking into account evaporation and infiltration into the soil. The input data are data on relief, land use structure, soil types, and time series of precipitation and air temperature; for calibration, time series of river runoff values ​​at control points of watercourses are required. For the catchment area of ​​each river (indicated above) a separate numerical installation was prepared and configured.Open information was used for calculations. The initial spatial data were processed using GIS. Sub-basin area, km2: Shuttle Radar Topography Mission data [Source: https://dds.cr.usgs.gov/]. Soil types, %: Unified State Register of Soil Resources of Russia [Source: https://egrpr.esoil.ru/index.htm]. Land use structure, %: Annual global land cover time series [Source: https://www.esa-landcover-cci.org/]The input information on the amount of precipitation (daily total) and air temperature (daily average) was based on measurements from meteorological stations located within the boundaries and near the Vistula Lagoon catchment area [Source: https://rp5.ru/Weather_in_the_world]. Data from 14 weather stations were used. Data from the four closest stations were simultaneously used for each individual sub-basin. Daily average temperature and precipitation data are defined as weighted averages, taking into account a coefficient depending on the distance to the station. The smaller the distance determines the higher weighting coefficient, and the higher the influence of the nearest station. Simultaneous use of data from several meteorological stations reduces measurement errors at each station.The calibration was made using daily measurement data from the state hydrological network in Russia [Source: https://gmvo.skniivh.ru/] and Poland [Source: https://hydro.imgw.pl/#/] for hydrological posts of the Nelma, Pregolya, Banówka-Mamonovka, Pasłęka, Bauda rivers for the period 2008–2021.The time period of hydrological modeling was 1991-2023. As a result, data for the outlet sections of the rivers flowing into the Vistula Lagoon were obtained and published for open use: Primorskaya, Nelma, Pregolya, Deyma, Prokhladnaya, Banówka-Mamonovka, Pasłęka, Bauda.Data on water discharge in the outlets of the rivers flowing into the Vistula Lagoon are presented as separate text files. Each file has a name corresponding to the name of the river. The attribute table consists of two columns: Date (in the year-month-day format) and Discharge (m3/s).