Danube Delta Monitoring system and knowledge of sediment flow spilled in the Black Sea

Organization: NIHWM - National Institute of Hydrology and Water Management / UDJG - The UGAL - ''Dunarea de Jos'' University of Galati (Romania)

Two Romanian institutions, National Institute of Hydrology and Water Management and University of Galati,  aim to enhance understanding of the sediment budget and transport through the Sulina branch into the Black Sea. Their research focuses on sediments and water,  developing special solutions for continuous monitoring of different parameters, prediction and forecasting models using ARIMA and deep-learning techniques. This includes creating frameworks to assess correlation of water and sediment quality, to apply these innovative methods to other pilots’ areas to support environmental management strategies and to know the sediment supply in the seas and oceans.

General Info

The site near the mouth of the Danube into the Black Sea serves as a "buffer zone" for the river-delta-sea system. The Danube splits into numerous branches, with the Sulina Branch being the most significant, reinforced to support ship navigation and prevent sediment deposition. This area is highly dynamic in terms of morphology, hydrology, and sedimentology, being monitored from the hydrological point of view by four main hydrometric stations. Favorable biological conditions, created by the permanent or almost permanent presence of water, promote the growth of delta-specific vegetation, making it a UNESCO World Heritage Site and a protected zone for various habitats and species.

What measures have been taken?

Research

• Analyze historical series of data (flow, sediment load, soil granulometry) to understand sediment dynamics evolution
• Monitoring the sediment quantity on different sections, during three hydrological regimes, to track sediments transport along the Sulina Branch

Improvement of sediment quantity monitoring

• Implementation a continuous monitoring system at the mouth of Sulina Branch to measure the temporal variability of the suspended solids transport to the Black Sea, as well as the water level, water salinity, water and air temperature
• Goal: to ensure continuous data about the suspended solids supply of the Black Sea, as well as the influence of the sea on the Danube water (salinity values)
• Impact: improve the knowledge of sediment transport to the Black Sea

Interrelation of Water and Sediment Quality

• Both water and sediment quality must be considered together to define an appropriate analytical framework and to estimate the quality of the sediments that reach the Black Sea
• The goal is to support decision-making and ensure continuous accurate data.

Predictive Models Development

• Develop predictive models for both water quality matrix and suspended sediment quality.
• Implement a deep learning (CNN - Convolutional Neural Network) based framework to identify water and sediment quality status within the Danube River study sector.

Analytical Framework Integration

• Integrate data related to sediment dynamics, like the results of the automated station, with data on water and sediment quality.
• Continue collecting data through in-situ sampling and continuous monitoring sensors to improve knowledge of the quantity and quality of sediments discharged into the Black Sea.
• Combine numerical and imagery data for comprehensive analysis.

Environmental Impact

High Economic Sustainability Solution

• Increase efficiency in environmental decision-making.
• Increase efficiency in navigation conditions maintenance
• Act as a decision support system for local/national administrations in relation with the main drivers for the sediment regime alteration

Data Utilization

• Continuous monitoring hydromorphological parameters  and granulometry data.
• Assess the ecological status of the site.
• Aid in creating future action plans.
• Optimize in-situ solutions.
• Identify and overcome barriers during replication activities.

Prediction Tools

• Improve capacity to respond to future threats.
• Propose new protection policies.
• Facilitate the reduction of chemical and morphological impacts on the Delta.

Recommendations

Sediment deposition is influenced by environmental and human factors. Continuous high-resolution monitoring of river outflows into the sea, using a continuous monitoring system with sensors and AI techniques, can determine sediment loads more accurately and adapt to other sites. Previous analytical methods are insufficient for a comprehensive assessment. The new sediment quality monitoring method  will involve citizens and stakeholders, adapt to emerging challenges, and enable frequent in-situ evaluations.