Storage basins

A Basin in a regional model stands for a whole network of waterways. To represent that water does not all flow at once, most Basins come in a pair, with the same area:

a doorgaand Basin for the flowing water, on the main route through the area, and
a bergend Basin for the stagnant water, in the ditches and small watercourses.

Precipitation, evaporation and groundwater reach them differently, see Forcing. In the coupled model, about 9800 of the 20 200 Basins are bergend, and 2300 are hoofdwater, the main water system and the KRW water bodies.

flowchart LR
  subgraph drain["Drains only"]
    b1["bergend"] -->|"TabulatedRatingCurve<br>Van der Gaast"| d1["doorgaand"]
  end
  subgraph both["Can also be supplied"]
    b2["bergend"] <-->|ManningResistance| d2["doorgaand"]
  end

The two ways in which a storage Basin connects to its doorgaand Basin.

Gravity controlled models

pipeline/05_add_bergend.py adds a storage Basin to each Basin with ribasim_nl.berging.VdGaastBerging, from the rasters of the LHM and of Van der Gaast. It drains through a TabulatedRatingCurve.

In the supply areas of verwerkt/sturing/aanvoergebieden.gpkg with meta_aanvoer true, the storage Basin connects with a ManningResistance instead, so it can also be supplied. A Basin counts as supplied if at least half of its area lies in a supply area, see ribasim_nl.berging.supply_area_basin_ids.

Level controlled models

The profile generation derives both profiles from the hydro-objects and the BGT, and adds the storage Basins, always with a ManningResistance. Without any usable profile, the Basin keeps one Basin with a fallback profile.