Introduce experimental config section and use it for concentrations.

core/src/config.jl

@@ -134,6 +134,19 @@ end
     use_allocation::Bool = false
 end
 
+@option struct Experimental <: TableOption
+    concentration::Bool = false
+end
+# For logging enabled experimental features
+function Base.iterate(exp::Experimental, state = 0)
+    state >= nfields(exp) && return
+    return Base.getfield(exp, state + 1), state + 1
+end
+function Base.show(io::IO, exp::Experimental)
+    fields = (field for field in fieldnames(typeof(exp)) if getfield(exp, field))
+    print(io, join(fields, " "))
+end
+
 @option @addnodetypes struct Toml <: TableOption
     starttime::DateTime
     endtime::DateTime
@@ -145,6 +158,7 @@ end
     solver::Solver = Solver()
     logging::Logging = Logging()
     results::Results = Results()
+    experimental::Experimental = Experimental()
 end
 
 struct Config

core/src/main.jl

@@ -40,6 +40,9 @@ function main(toml_path::AbstractString)::Cint
                     @warn "The Ribasim version in the TOML config file does not match the used Ribasim CLI version." config.ribasim_version cli.ribasim_version
                 end
                 @info "Starting a Ribasim simulation." toml_path cli.ribasim_version starttime endtime
+                if any(config.experimental)
+                    @warn "The following *experimental* features are enabled: $(config.experimental)"
+                end
 
                 try
                     model = run(config)

core/src/write.jl

@@ -5,7 +5,7 @@ Write all results to the Arrow files as specified in the model configuration.
 """
 function write_results(model::Model)::Model
     (; config) = model
-    (; results) = model.config
+    (; results, experimental) = model.config
     compress = get_compressor(results)
     remove_empty_table = model.integrator.t != 0
 
@@ -25,9 +25,11 @@ function write_results(model::Model)::Model
     write_arrow(path, table, compress; remove_empty_table)
 
     # concentrations
-    table = concentration_table(model)
-    path = results_path(config, RESULTS_FILENAME.concentration)
-    write_arrow(path, table, compress; remove_empty_table)
+    if experimental.concentration
+        table = concentration_table(model)
+        path = results_path(config, RESULTS_FILENAME.concentration)
+        write_arrow(path, table, compress; remove_empty_table)
+    end
 
     # discrete control
     table = discrete_control_table(model)

core/test/docs.toml

@@ -48,3 +48,7 @@ verbosity = "info" # optional, default "info", can otherwise be "debug", "warn"
 # These results files are always written
 compression = true  # optional, default true, using zstd compression
 compression_level = 6 # optional, default 6
+
+[experimental]
+# Experimental features, disabled by default
+concentration = false # tracer calculations

docs/_quarto.yml

@@ -32,6 +32,7 @@ website:
         - install.qmd
         - changelog.qmd
         - known_issues.qmd
+        - contact.qmd
 
     - title: "Tutorials"
       contents:

docs/concept/core.qmd

@@ -120,21 +120,29 @@ allocation_subNetwork->>user_demand: allocated
 user_demand->>basin: abstracted
 ```
 
-# Substance (tracer) concentration calculations
+# Substance (tracer) concentrations
+
+::: {.callout-caution}
+This is an unsupported experimental feature and is disabled by default.
+We advise to use the [Delwaq coupling](@sec-waterquality) for tracer calculations.
+If you're interested in using this experimental feature, please [contact us](/contact.qmd).
+:::
 
 Ribasim can calculate concentrations of conservative tracers (i.e. substances that are non-reactive).
 It does so by calculating the mass transports by flows for each timestep, in the `update_cumulative_flows!` callback.
-Specifically, for each Basin at each timestep we calculate:
+Specifically, for each Basin at each timestep it calculates:
 
-- all mass inflows (flow * source_concentration) given the edge inflows
-- update the concentrations in the Basin based on the added storage (previous storage + inflows)
-- all mass outflows (flow * basin_concentration_state) give the edge outflows
+- all mass inflows ($flow * source\_concentration$) given the edge inflows
+- update the concentrations in the Basin based on the added storage ($previous storage + inflows$)
+- all mass outflows ($flow * basin\_concentration\_state$) give the edge outflows
 - update the concentrations in the Basin based on the current storage
 
 We thus keep track of both mass and concentration of substances for each Basin.
 Note that we have not added the substance mass to the states, and we assume that concentrations of flows are piecewise constant over a timestep.
+This excludes the use of tracer injections.
+
+By default the following source tracers are enabled.
 
-By default we calculate concentrations for the following source tracers.
 - Continuity (mass balance, fraction of all water sources, sum of all other source tracers)
 - Initial (fraction of initial storages)
 - LevelBoundary, FlowBoundary, UserDemand, Drainage, Precipitation (fraction of different boundaries)

docs/guide/coupling.qmd

@@ -6,7 +6,7 @@ title: "Coupling"
 
 Ribasim can also be (online) coupled to other kernels with the help of iMOD Coupler. The corresponding documentation can be found within the [iMOD Suite Documentation](https://deltares.github.io/iMOD-Documentation/coupler.html).
 
-# Water quality
+# Water quality {#sec-waterquality}
 
 Ribasim can be offline coupled to Delwaq, the Deltares Water Quality model.
 

docs/reference/usage.qmd

@@ -80,6 +80,23 @@ entry             | type   | description
 ----------------- | ------ | -----------
 verbosity         | String | Verbosity level: debug, info, warn, or error.
 
+## Experimental features
+
+::: {.callout-important}
+Experimental features are completely unsupported. They can break at any time
+and results will be wrong. **Do not use them in production**. If you're interested
+in using an experimental feature, please [contact us](/contact.qmd).
+:::
+
+One can enable experimental features in the `[experimental]` section.
+Currently the following features can be enabled (all are disabled by default).
+
+entry             | type   | description
+----------------- | ------ | -----------
+concentration     | Bool   | Whether to enable tracer calculations or not.
+
+
+
 # GeoPackage database and Arrow tables {#sec-geopackage}
 
 The input and output tables described below all share that they are tabular files. The Node

python/ribasim/ribasim/config.py

@@ -144,6 +144,19 @@ class Logging(ChildModel):
     verbosity: Verbosity = Verbosity.info
 
 
+class Experimental(ChildModel):
+    """
+    Defines experimental features.
+
+    Attributes
+    ----------
+    concentration : bool
+        Whether to enable tracer support (default is False)
+    """
+
+    concentration: bool = False
+
+
 class Node(pydantic.BaseModel):
     """
     Defines a node for the model.

python/ribasim/ribasim/model.py

@@ -26,6 +26,7 @@
     Basin,
     ContinuousControl,
     DiscreteControl,
+    Experimental,
     FlowBoundary,
     FlowDemand,
     LevelBoundary,
@@ -86,6 +87,8 @@ class Model(FileModel):
 
     allocation: Allocation = Field(default_factory=Allocation)
 
+    experimental: Experimental = Field(default_factory=Experimental)
+
     basin: Basin = Field(default_factory=Basin)
     continuous_control: ContinuousControl = Field(default_factory=ContinuousControl)
     discrete_control: DiscreteControl = Field(default_factory=DiscreteControl)