For the tidal areas of the tidal valley, the Lesum-Wümme-Hamme river system and the Ochtum river, the following tasks are to be carried out: (A) Preparation: Preparation, review and description of the input data for the system state of the hydrological year 2020 (01.11.2019 up to and including 31.10.2020). (B) Model construction: Creation of one numerical model each for the Tidehunte (3D), the Lesum-Wümme-Hamme river system (2D) and for the Ochtum (2D) - a total of 3 independent models. Delft3D-Flexible Mesh (Delft3D-FM) is to be used as a model system in order to enable later use / further use of the created models by the BAW. (C) Simulation: Determination of the hydrodynamic system parameters (water level, flow velocity, transport capacity, flow rate) for four different scenarios (actual planning state, expansion of the Outer Weser, expansion of the Lower Weser North, overlay of the expansion of the Outer Weser and Lower Weser North) over 2 spring-nipp cycles each. For the Hunte, two further scenarios with sea-level rise for salt intrusion are also to be expected. (D) Hydraulic system analysis: Determination of the tidal parameters of the water level, the flow and the transport capacity as well as their change due to the planned expansion variants. (E) Transfer of the model result data and the models including a handover protocol with a data description. (F) Documentation: Preparation of a report summarizing all investigations, results and methods used.

See II.1.4)