Search Results (8)

Satellite-derived bathymetry (SDB) enables the efficient mapping of shallow waters such as coastal zones but typically requires extensive local ground truth data to achieve high accuracy. This study evaluates the effectiveness of transfer learning in reducing this requirement while keeping estimation accuracy at acceptable levels by adapting a deep learning model pretrained on data from Puck Lagoon (Poland) to a new coastal site in Agia Napa (Cyprus). Leveraging the open MagicBathyNet benchmark dataset and a lightweight U-Net architecture, three scenarios were studied and compared: direct inference to Cyprus, site-specific training in Cyprus, and fine-tuning from Poland to Cyprus with incrementally larger subsets of training data. Results demonstrate that fine-tuning with 15 samples reduces RMSE by over 50% relative to the direct inference baseline. In addition, the domain adaptation approach using 15 samples shows comparable performance to the site-specific model trained on all available data in Cyprus. Depth-stratified error analysis and paired statistical tests confirm that around 15 samples represent a practical lower bound for stable SDB, according to the MagicBathyNet benchmark. The findings of this work provide quantitative evidence on the effectiveness of deploying data-efficient SDB pipelines in settings of limited in situ surveys, as well as a practical lower bound for clear and shallow coastal waters. Full article

The transport of pollutants with flowing waters is one of the most common processes in the natural environment. In general, this process is described by a system of differential equations, including the continuity equation, dynamic equations, pollutant transport equations and equations of state. For the analyzed problem of pollutant migration in wide rivers and the coastal zone, a two-dimensional model is particularly useful because the velocity and mass concentration profile is vertically averaged. In this model, taking into account the dispersion flux leads to appropriate equations, and the dispersion process is described by the dispersion tensor. Due to the transverse isotropy of the dispersion process, the coordinates of this tensor are expressed in terms of local dispersion coefficients along the direction of the velocity and in the direction perpendicular to it. Commonly used methods for determining mass dispersion coefficients refer to a gradient velocity profile, typical for rivers. However, in the coastal zone, the velocity profile changes from gradient to drift when shear stresses on the surface caused by the wind begin to dominate. The drift profile also occurs in estuaries, where there is a difference in the density of fresh and salt water. This paper analyzes the numerical solution of the two-dimensional dispersion equations in the coastal zone for the dispersion coefficients adopted for the gradient and drift velocity profiles and then assesses how this affects the final result. Four typical scenarios of pollutant migration in the coastal zone of the Bay of Puck are presented. The calculated dispersion coefficients differ significantly depending on the adopted velocity profile: for the gradient, D_LG = 0.17 [m²/s], and for the drift, D_LD = 89.94 [m²/s]. Full article

The relationship between air temperature (mainly winter, December-March) in Świnoujście, Gdynia, and Elbląg and ice parameters (dates of the first ice and disappearance of the last ice, the length of the ice season, number of days with ice, maximum ice height) of southern Baltic coastal lagoons (Szczecin, Puck, and Vistula) was investigated. Trends in these parameters were determined, too. The observation material comes from the archives of the Institute of Meteorology and Water Management and spanned the winters from 1950/51 through to 2019/20. Relationships between the selected ice parameters for the study basins and the values of air temperature were examined using correlation and regression methods. The regression equations and trends, as well as their correlation and determination coefficients, were determined. The statistical significance of these relationships was examined using the Fisher-Snedecor test. Strong correlations between ice parameters values and air temperature were obtained, characterized by high values of both correlation coefficients and statistical significance. All trends of ice parameters indicate mitigation of ice conditions. An acceleration in both temperature and ice condition mildening occurred in the late 1980s, and especially in the last years of the study period. These trends, except the first ice date, are statistically significant, some even at α < 0.001. The length of the ice season becomes significantly shorter, the number of days with ice and the maximum thickness is smaller, and the last ice is disappearing early. An increase in the correlation and determination coefficients and a characterized trend of ice parameters values towards the East was found. It shows the increased impact of a warming climate in this direction on the southern Baltic coast. Strong correlations and trends may be of prognostic significance. Full article

The aim of this study was to determine the correlation between the meteorological factors and the number of molds and yeast-like fungi in the air in the five coastal towns in the years 2014–2017, and in 2018, after emergency disposal of raw sewage to the Gdańsk Gulf. In the years 2014–2018, a total number of 88 air samples were collected in duplicate in the five coastal towns of Hel, Puck, Gdynia, Sopot, and Gdańsk-Brzeźno. After the application of the (PCA) analysis, this demonstrated that the first principal component (PC1) had a positive correlation with the water temperature, wind speed, air temperature, and relative humidity. The second principal component (PC2) had a positive correlation with the relative humidity, wind speed, wind direction, and air temperature. In 2018, potentially pathogenic mold and yeast-like fungi (Candida albicans, Stachybotrys chartarum complex, Aspergillus section Fumigati) were detected in the seaside air. While the detected species were not observed in the years 2014–2017. We suggest that it is advisable to inform residents about the potential health risk in the event of raw sewage disposal into the water. Moreover, in wastewater treatment plants, tighter measures, including wastewater disinfection, should be introduced. Full article

This paper describes the ecohydrodynamic predictive model EcoPuckBay—the ecosystem part—for assessing the state of the Puck Bay coastal environment and its ecosystem. We coupled the EcoPuckBay model with the land water flow models (Soil and Water Assessment Tool (SWAT) for surface water and Modflow for groundwater). To evaluate the quality of the results obtained from the EcoPuckBay model, a set of basic statistical measures for dissolved oxygen, chlorophyll-a, nitrates, and phosphates were calculated, such as mean, Pearson correlation coefficient (r), root-mean-square-error (RMSE), and standard deviation (STD). The analysis presented in this paper shows that the EcoPuckBay model produces reliable results. In addition, we developed a nutrient spread module to show the impact of agricultural activity on the waters of the Puck Bay. The EcoPuckBay model is also available in operational mode where users can access 60-h forecasts via the website of the WaterPUCK Project through the “Products” tab. Full article

This study focuses on the modeling of groundwater flow and nitrate transport in a multi-aquifer hydrosystem in northern Poland, adjacent to Puck Bay (Baltic sea). The main goal was to investigate how changes in land use and farming practices may affect groundwater recharge and submarine groundwater discharge (SGD) to the sea and the associated N-NO₃ fluxes. An integrated modelling approach has been developed, which couples the SWAT hydrologic model, MODFLOW-NWT groundwater flow model, and MT3DMS transport model. Transient simulations were performed for a 10 y period, assuming 10 different scenarios of land use (farming, grassland, forest) and crop types. Both recharge and SGD showed a distinct pattern of seasonal time variability. In terms of the average flow rates, the effect of varying crop type was more significant than that of land use change, with the minimum recharge and SGD corresponding to winter wheat and the maximum for peas and potatoes. Nitrate loads were strongly affected by both land use and crop type, with minimum values obtained for grassland and maximum values for canola. Full article

Coastal basins are particularly exposed to the adverse impact of anthropogenic stress. In many places, despite only the seasonal increase in the number of residents, progressive urbanization and associated changes in the catchment characteristics are noticeable. Puck Bay is part of the Gulf of Gdansk and belongs to the Baltic Sea. Although the area of Puck Bay is covered by the Natura 2000 Network, this has not saved it from eutrophication problems. As part of the work on a complex coastal basin analysis (WaterPUCK project), the Soil and Water Assessment Tool (SWAT) model was used to determine the agricultural impact on water quality in rivers with a flow into Puck Bay: Reda, Gizdepka, Płutnica, and Błądzikowski Stream. The results include the loads of nutrients and pesticides that flow out from the agricultural areas of Puck community into Puck Bay. In this article, special attention has been paid to the impact of precipitation on the quality of water at the outflow of rivers into the Bay of Puck, because it is a decisive element in the amount of nutrients leached along with surface runoff to watercourses and then into the Gulf. The distribution of precipitation thus affects the amount of nutrients absorbed by plants. Modeling the effects of agricultural practices, taking into account long-term meteorological forecasts, is helpful in attempts to reduce the amount of pollutants entering the Baltic Sea. Full article

In recent years, thanks to the enormous computational power of modern supercomputers, modeling has become one of the most highly evolving scientific fields. It is now possible to describe relatively large physical bodies and to study the changes occurring in these bodies with resolution never attainable before. The paper describes the initial implementation of the EcoPuckBay model system and presents the results of the model simulations compared to observations from monitoring stations and other model reanalyses. High correlation between model results and observations has been confirmed both in terms of spatial and temporal approach. Data acquired via simulations of the EcoPuckBay model was deployed in the project archive database. The dedicated service was created, allowing the user to visualize all produced hydrodynamic parameters as raster maps, time series, and/or cross-sections. This functionality is available online via the official WaterPUCK project website in the services web section. In the next stage of the project, this service will be upgraded to an operational state and forecasts will be added. Full article