KAREL - Climate adaptation of the rainwater network of Elmshorn and surroundings | Umweltbundesamt

As part of the predecessor project KLIMZUG-NORD, climate projections were produced using the dynamic regionalized climate models REMO and CLM. The scenarios A1B, A2 and B were examined. The climate change signals were evaluated at the middle as well as at the end of the 21st century. The reference period used was the C20 scenario, which covers the climate of the years 1971 to 2000.
In addition, further results of climate model simulations were used within the framework of KAREL and analysed in detail in order to deepen the already existing knowledge. These simulation results, which are also based on the REMO climate model, are based on the RCP scenarios RCP2.6, RCP4.5 and RCP8.5.

As a result of the predecessor project KLIMZUG-NORD, it has become clear that the municipalities in the KAREL study area will first of all get a problem with the drainage of rainwater from the point of view of climate change.
In the first step, the expected effects of climate change on the drainage situation in the KAREL study area were presented for the development of the climate adaptation concept. For this purpose, numerical models for the mapping of the actual state were created and subsequently the expected effects of climate change on the system were determined.

In the first step, generally conceivable solutions for each of the three subareas within the KAREL study area (upper reaches of the Krückau, in which a typical Geest area drains; Krückau section of Elmshorn, drained into the urban sewer network, under the Krückau, in which a typical marsh area drains) were worked out and discussed. In the targeted development of practicable adaptation measures, the necessary background knowledge and the required detailed local knowledge of the city of Elmshorn as well as the technical knowledge of the TUHH on fundamental adaptation measures to the consequences of climate change were incorporated. With a view to a later high probability of realization of the individual adaptation measures, this process of preparation and discussion took place from the very beginning in close cooperation with the local experts and stakeholders.
In the next step, a selection of basically suitable adaptation measures was implemented in the numerical models for each of the three subareas. On the basis of the resulting simulation results, the respective adaptation measures were analyzed and evaluated for their effectiveness.
Based on the findings, the individual measures for each of the three study areas were then merged into a separate action plan. These action plans were then further developed into an integrated and spatially comprehensive climate adaptation concept, taking into account the interactions with each other.