WATERWAY
Waterways are important routes for the transport of goods and people, as they offer cost-effective and environmentally friendly alternatives to road and rail transport. They play a crucial role in the economy by facilitating trade and connecting inland regions to seaports.
The functionality of waterways depends on several factors, including sufficient water depth and width to allow for ship traffic, as well as regular maintenance and care to avoid obstacles such as sediment deposits. In addition, functioning hydraulic structures such as groynes, locks, and other infrastructure components are crucial to ensure both smooth and safe transport and the flood safety of adjacent residential areas. Technical measures to optimize navigation conditions (water depth in the navigation channel during low water conditions) include especially guide structures and groynes. The former direct the flow in the desired direction, while the latter concentrate the flow in the middle of the river, thereby increasing the water level.
Digital Waterway
The positions of all ships on the Danube are continuously recorded electronically via the DoRIS (Danube River Information Services) system and displayed on an electronic inland navigation chart, the Inland-ECDIS. This is achieved through the targeted use of satellite positioning, data radio, and adapted visualization. The analysis of the data generated in this way reveals the extent to which the marked navigation route is adhered to or whether optimizations to its course are necessary, which increases traffic safety on the Danube.
Waterway Monitoring
Monitoring of waterways is crucial to ensure the safety and efficiency of ship traffic. Continuous monitoring of navigation channel depths is necessary to ensure that ships have sufficient draft and do not run aground. The morphology of the waterways, that is, the shape and structure of the riverbed, must also be regularly examined, as changes due to erosion or sedimentation can affect navigability. The wave action generated by passing ships can damage shore areas and structures, which is why its effects must be closely observed and regulated. Numerical modeling plays a central role in this, as it allows for the simulation of complex hydrodynamic processes and predictions about future changes.
Hydraulic Engineering to Optimize Navigation Conditions
While traditional construction of groynes has an inclining or orthogonal straight form to deflect the flow away from the bank, more recently, declining or curved groynes are also being constructed to, for example, allow targeted and controlled erosion of sediment at the bank areas, thereby compensating for an existing sediment deficit in the river course and improving the ecological conditions in the bank area. The design of hydraulic structures has a significant impact on the flow and sediment transport in rivers, and careful planning and optimization are necessary to achieve the desired ecological and engineering objectives.
Flexible Infrastructure in the Waterway
Historically, a type of flexible infrastructure was already in use at the beginning of the 20th century in Vienna at the Nussdorf location. During floods, a floating gate was placed across the beginning of the Danube Canal to prevent the entry of drift ice into the city. This topic is now being revisited in a contemporary context, as modern hydraulic engineering aims to keep interventions minimal while still fulfilling their purpose. The background for this is the sediment balance that has become unbalanced in many rivers. Modern sediment management serves both flood protection and the improvement of navigation and ecology, but it also requires costly maintenance or hydraulic engineering measures. A common measure to ensure the necessary navigation channel depths in the waterway is low water regulation using groynes. They are responsible for concentrating the water in the main stream at low flows/water levels. However, at higher flows, they are often even counterproductive. Areas along the waterway that require infrastructural measures (e.g., areas of sediment deposition) can also vary. Therefore, Viadonau is trying to include flexible infrastructure elements in its modern waterway management. The IWA supports this with accompanying research through on-site monitoring to make direct effects visible and by developing numerical as well as physical models to enable variant planning.