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Plot a load-response curve for a reservoir

Source: R/plot.R
ok_plot_response.Rd

ok_plot_response() generates a load-response curve showing how predicted in-lake chlorophyll-a, Secchi depth, or mean TSI responds to a range of inflow total phosphorus concentrations. This is the core planning tool for answering "what inflow TP concentration achieves a given trophic state target?"

The curve is generated by running the full okBATHTUB pipeline across a sequence of TP concentrations while holding all other parameters constant at the baseline values.

Usage

ok_plot_response(
  baseline,
  response = c("chla", "secchi", "tsi", "tp_inlake"),
  tp_range = c(10, 300),
  n_points = 100L,
  target_tsi = NULL,
  target_class = NULL,
  show_trophic_bands = NULL,
  current_tp = NULL,
  lake_name = NULL
)

Arguments

baseline

An okBATHTUB object that has been run through at least ok_hydraulics(). Morphometry and coefficient set are taken from this object.

response

One of "chla" (chlorophyll-a, ug/L), "secchi" (Secchi depth, m), "tsi" (mean Carlson TSI), or "tp_inlake" (in-lake TP, ug/L). Default "chla".

tp_range

Numeric vector of length 2. Range of inflow TP concentrations to plot (ug/L). Default c(10, 300).

n_points

Integer. Number of points along the curve. Default 100.

target_tsi

Numeric. Optional horizontal reference line showing a TSI target. Only shown when response = "tsi".

target_class

Character. Trophic class target. Sets target_tsi automatically. One of "oligotrophic", "mesotrophic", "eutrophic".

show_trophic_bands

Logical. Show coloured trophic state background bands on TSI plots. Default TRUE when response is "tsi".

current_tp

Numeric. Optional vertical reference line showing the current inflow TP concentration.

lake_name

Character. Lake name for plot title. Default NULL.

Value

A ggplot2 object.

See also

ok_scenario, ok_plot_scenario

Examples

# \donttest{
baseline <- ok_load(
  inflow_m3yr   = 45e6,
  tp_inflow_ugl = 120,
  coefficients  = "oklahoma",
  ecoregion     = "Cross Timbers"
) |>
ok_hydraulics(surface_area_ha = 890, mean_depth_m = 4.2)

ok_plot_response(baseline, response = "tsi",
                 target_class = "mesotrophic",
                 current_tp   = 120,
                 lake_name    = "Arcadia Lake")

# }