Navigability of inland waterways
The navigability of inland waterways can be restricted by both low water and high water. Since restrictions due to floods are usually of shorter duration, they have less economic significance than low-water events. Restrictions due to low water have lasted more than 100 days in individual years, in the case of floods no more than 14 days.
During long dry periods, water levels and flow velocities in the waterways decrease. Even low water can mean that ships can no longer be fully loaded. The reduced river width restricts the possibilities for meeting and overtaking, which in turn leads to low travel speeds. The restrictions on inland navigation can sometimes have a significant impact on individual companies or entire production and supply chains. These can range from increased transport costs to production losses in companies with just-in-time production. Especially for the Rhine and the Danube, there will be increased restrictions on navigability in the future.
During floods, the water levels and flow velocities in the rivers rise. If this endangers traffic safety, buildings near the banks or bridge clearance heights, navigation will be stopped. Since floods do not usually last that long, they have less economic relevance for shipping. The inland and maritime waterways themselves as well as ports and maritime infrastructures can also be damaged by floods.
Indicator from the monitoring on the DAS: Flood closures and low water restrictions on the Rhine
Damage to roads and railways
Damage or obstructions to roads and railways can result from floods caused by heavy rainfall or landslides. Direct damage to federal infrastructure, such as railways, trunk roads and federal waterways, for example, caused around one billion euros in 2002 and 0.3 billion euros in 2013.
Floods can lead to flooding and undermining of transport infrastructure and thus impair traffic flow. Subways and tunnels are particularly at risk, and the risk of accidents on roads can increase due to aquaplaning. Undercutting of transport routes can reduce the stability of railway embankments, track beds and roads. At the same time, they also affect the stability of the ground and can thus trigger landslides or slope slides, for example, which can damage the transport infrastructure and lead to accidents.
Indicator from the monitoring on the DAS: Heavy rain and roads, Weather-related road traffic accidents, Impacts on roads from extraordinary weather events – case study
Damage to traffic guidance systems, overhead lines and power supply systems
Traffic guidance systems (e.g. traffic lights and signs), overhead lines and power supply systems (e.g. power pylons) are particularly affected by periods of heat, drought, storms and thunderstorms as well as cold periods with heavy snowfall. Damaged traffic installations impede the flow of traffic and can cause accidents. Damaged electricity pylons can cause the power supply to collapse in entire regions.
Hot spells can cause material damage to traffic control systems and power supply installations. Drought makes vegetation more susceptible to wind breaks. Storms and the resulting wind breakage of trees can cause direct damage to free-standing poles, overhead lines and traffic control systems. Weather-related damage to overhead lines leads to the temporary loss of rail traffic and thus to restrictions in passenger and freight transport. Excessive snow and ice loads weigh down masts, traffic control systems and overhead lines and can cause damage. Lightning strikes can cause interruptions in the power supply to traffic control systems.
Other climate impacts
Navigability of sea shipping lanes: Sea-level rise will raise both high and low tides, so that the accessibility of ports will not be altered. Increased sediment transport may increase the cost of maintenance dredging for the sea lanes.
Damage to inland and maritime waterways, ports and maritime infrastructures: Maritime waterways, ports and maritime infrastructures will be increasingly exposed to the effects of sea-level rise in the future. For inland waterways, the expected increase in heavy precipitation may result in increased risks of damage from flood events and flooding.