Climate changes relevant to the action field

State: Heat and Drought

Germany is experiencing an increase in the frequency of hot and dry years. When high temperatures occur in tandem with negligible precipitation in summer as for instance in 2018, 2019 and latterly also 2022 (cf. figure 4), this can entail intensive and also extensive dry phases with low soil humidity. In Germany, the mean of days recorded with low soil humidity has increased significantly since 1961 (cf. figure 10). In the years mentioned, there were other drought symptoms such as little groundwater recharge and low groundwater levels (cf. Indicator WW-I-2) as well as distinct low-water phases; the hot and dry summers of 2018 to 2020 have entailed three years in which extremely low water levels were recorded (cf. Indicator WW-I-6).

Impacts of climate change

Impact: VE-I-2 Low-water restrictions to shipping on the Rhine

In cases when large areas of the Rhine catchment area lack precipitation over extended periods, combined with long spells of high temperatures, this can bring about long-lasting situations when water levels remain low. As far as shipping is concerned, low water levels in the Rhine require low payloads, as the low water levels enforce constraints on a ship’s draught. This may lead to supply bottlenecks and price increases for goods transported by inland shipping.

Adaptations – activities and results

Action Plan ‘Rhine Low-Water Levels’

In summer 2019, a year after the massive constraints imposed on Rhine shipping owing to low water levels and the economic impacts associated with this problem, the Rhine low-water levels action plan was proposed by the ⁠BMVI⁠ (Federal Ministry for Transport and Digital Infrastructure) – in authority at the time. Eight measures were developed in cooperation with representatives from major industrial enterprises in the Rhine catchment area and entities with responsibility for the inland shipping sector, in order to configure a more reliable and future-proof design of the requirements for goods transport on the Rhine.

The maintenance and further development of forecasting systems formed a major building block in this process. Early detection of extreme drainage situations plays an important role in the management of medium and low water levels and in transport planning. This enables enterprises to revise their planning in time, or – subject to availability – to allocate smaller ships with more convenient draught specifications for this scenario. Besides, additional storage capacities can assist in bridging bottlenecks in cases where shipping is exposed to severe constraints.