Sediment Transport Mechanisms in a Lagoon with High River Discharge and Sediment Loading

Abstract

The aim of this study was to investigate the sediment dynamics in the largest lagoon in Europe (Curonian Lagoon, Lithuania) through the analysis of in situ data and the application of a sediment transport model. This approach allowed to identify the propagation pathway of the riverine suspended sediments, to map erosion-accumulation zones in the lagoon and calculate the sediment budget over a 13-year-long simulation. Sampled suspended sediment concentration data are important for understanding the characteristics of the riverine and lagoon sediments, and show that the suspended organic matter plays a crucial role on the sediment dynamics for this coastal system. The numerical experiments carried out to study sediment dynamics gave satisfactory results and the possibility to get a holistic view of the system. The applied sediment transport model with a new formula for settling velocity was used to estimate the patterns of the suspended sediments and the seasonal and spatial sediment distribution in the whole river–lagoon–sea system. The numerical model also allowed understanding the sensitivity of the system to strong wind events and the presence of ice. The results reveal that during extreme storm events, more than 11.4 × 106 kg of sediments are washed out of the system. Scenarios without ice cover indicate that the lagoon would have much higher suspended sediment concentrations in the winter season comparing with the present situation with ice. The results of an analysis of a long-term (13 years) simulation demonstrate that on average, 62% of the riverine sediments are trapped inside the lagoon, with a marked spatially varying distribution of accumulation zones.

Zebra Mussel Holobionts Fix and Recycle Nitrogen in Lagoon Sediments

“…Sediment and zebra mussel specimens were collected in June 2018 at a fine-sand site (median grain size 0.238 mm) from a shallow area (1.2 m depth) of the oligohaline Curonian Lagoon (55 • 20 25.9 N, 21 • 11 24.4 E). The Curonian Lagoon, is a microtidal, low-energy system, characterized by a reduced vertical mixing in particularly in the summer months when the discharge from tributaries and wind intensity are at minimum (Ferrarin et al, 2008;Mezine et al, 2019). At the time of sampling, water temperature was 22.5 • C, salinity was 0.2, concentration of dissolved organic and inorganic nitrogen (i.e., DON and DIN) was 57.2 ± 0.7 (Mean ± SEM) and 1.8 ± 0.1 µM, respectively.…”

Approach of Ensuring Interoperability of Multi-Dimensional Data Warehouses for Monitoring of Water Resources

“…The influencing factors from air and soil pollution have straight relation for quality of open reservoirs of water and influence the quality of groundwater bodies. In respect of such influencing factors, some works can be mentioning by (Baltrėnas et al, 2017) in the area of development of DSS of air pollution, by (Marčiulaitienė et al, 2016;Mėžinė et al, 2019) in the analysis of pollution of Baltic Sea region. Ideas of MULINO project by (Mysiak et al, 2005) are helping in the area of environment protection, paying more attention in concrete aspects of water resources management.…”

Bathymetry Time Series Using High Spatial Resolution Satellite Images

“…Due to its high degree of automation and flexibility, it can be applied to the surveying and mapping of water depth. The Massachusetts Institute of Technology has developed a prototype ARTEMIS [84]; it is a small unmanned sounding vessel used in water-depth measurement. This idea has been…”

“…Due to its high degree of automation and flexibility, it can be applied to the surveying and mapping of water depth. The Massachusetts Institute of Technology has developed a prototype ARTEMIS [84]; it is a small unmanned sounding vessel used in water-depth measurement. This idea has been developed into different types of small unmanned ships, boats, or catamarans [85][86][87], such as the IMIDA06 USV [88] used in this study ( Figure 2).…”