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floodam.agri produces flood damage functions for agricultural plots from in-depth expert knowledge on crop vulnerability to hazard parameters (velocity, height, duration and seasonality).

This tool has been used to build the french national damage functions to the agricultural sector (Agenais et al. 2013 ; Brémond et al. 2022).

This vignette provides the basic steps to build a damage function to an agricultural plot. For this example, we will build damage functions for both greenbean and greenpea.

Declaring paths

The process starts by providing the input and output directories. After loading the library, use init_path() to initialize all the paths needed to obtain the damage functions.

To make things easier, floodam.agri is shipped with data available in your library’s installation folder. In this example we will use the inputs in the default folder which contains the necessary inputs to build any available damage function which includes greenbean and greenpea crops.

You will also need to provide a folder where the output of floodam.agri can be stored (our example uses a temporary directory):

#> Loading required package: floodam.agri
library(floodam.agri)

#> Setting up environment paths (inputs and outputs)
output = file.path(tempdir(), "get_started")
path = init_path(
  output = output,
  default = TRUE
)

For more information on the specifics and outputs of init_path(), please refer to: Understanding path declaration with init_path().

Preparing data

The next step is to read and prepare data needed to build the available damage functions and store them in the output folder. Among other things, this helps keep track of which inputs are used for each simulation. The functions to be called are the following: prepare_culture(), prepare_calendar(), prepare_typology() and prepare_action_value().

Run the chunk below to prepare data needed for building the damage functions.

#> Extracting damagement files to output
prepare_culture(path)

#> Extracting and copying calendars to output
prepare_calendar(path)

#> Building weight files
prepare_typology(path)

#> Preparing necessary action values and yields
prepare_action_value(path)

You can take a look at the prepared data in the output directory.

As you can see in path[["output"]][["culture"]], all available crops in the default folder have been prepared. If you wish to limit the number of prepared crops, you will need to specify the typo argument in prepare_culture(), prepare_calendar() and prepare_action_value(). This is covered in the vignette “Understanding inputs for floodam.agri” which gives more information on the specifics and outputs of these functions.

Building damage functions

The function calculate_damaging() builds damage functions for the crops of the declared extent. By default, culture is set to NULL in order to build damage functions for all the crops that were prepared in the previous step. Instead of building all possible damage functions, you can choose to build damage functions for specific crops by specifying them in the culture argument. In our example, we will set culture to build the damage functions for greenbean and greenpea.

For the purpose of our example, we will simplify the default flood resolution so that the running time is shorter (generally 4 to 10 seconds per crop with normal settings). This is done by changing the loaded global data stored in the LEVEL variable.

#> Simplifying LEVEL
LEVEL[["duration"]] = seq(0, 5, 1)
LEVEL[["height"]] = seq(0, 100, 10)
LEVEL[["week"]] = seq(2, 52, 2)

#> Calculating damage function
damaging = calculate_damaging(
  path,
  culture = c("greenbean", "greenpea"),
  level = LEVEL,
  update.hazard = TRUE,
  retrieve = TRUE
)
#> Update of culture damaging functions:
#>  Processing greenbean... Finished in 0.77 secs
#>  Processing greenpea... Finished in 0.76 secs
#> ... processed in 1.53 secs

Congratulations, you have built your first damage functions !

They are stored in path[["output"]][["damage"]]. By default, three data.frames for each crop are saved:

  • full/damage_crop.csv
    • damage function and associated damaging rules
  • sumup/damage_crop.csv
    • total damage function
  • sumup/damage-disaggregated_crop.csv
    • total and disaggregated (yield, replanting, soil and material) damage function

As you can see in the table below which shows the disaggregated result of calculate_damaging() for a greenbean plot, the produced damage functions do not have any hazard parameters in them. The hazard parameters associated to each row of these data.frames are available in the data.frame file.path(path[["output"]][["damage"]], "hazard.csv")

Disaggregated result of calculate_damaging()

Combining damage functions

This step has the main purpose of associating the produced damage functions for each crop together with the associated hazard parameters.

#> Combine damage to new classification
combine = combine_damaging(
  path = path,
  damage.culture = damaging,
  retrieve = "total" # one of c("total", "yield.annual", "yield.differed",
  # "replanting", "soil", material")
)
#> Processing combinations of damaging curves...    ... Finished in 0.2863789 secs

combine_damaging() exports one combined damage curve for each damage type c("total", "yield.annual", "yield.differed","replanting", "soil", material"). They can be found in the following output folder: path[["output"]][["combine"]]

In the table below is a glimpse of what the combine object is: combined damage functions of “total” damage for all crops selected in simulation and their associated hazard parameters.

Aggregating the damage functions

Finally, the raw damage functions can be aggregated by regrouping the hazard parameters into classes with the aggregate_damage() function. In this example we use the default aggregation parameters which aggregate by season (winter, spring, summer, autumn), velocity (light, middle, strong) and duration (short, middle, long, extra).

#> Aggregate damage
agg_damaging = aggregate_damage(
  path,
  damage_origin = "total" # default
)

The result is saved in path[["output"]][["combine"]] under the name total.aggregate.csv because the damage type that is aggregated by default is the total damage. Feel free to run this function again by setting damage_origin to one of c("material", "replanting", "soil", yield.annual", "yield.differed").

The result is shown in the table below.

Basic visualisation

Aggregated damage curves

floodam.agri comes with a default visualisation function called plot_aggregated_damage() which creates a plot of aggregated damage.

#> Show plot
plot_aggregated_damage(
  path = path,
  damage = "total.aggregate", # default
  culture = "greenpea",
  current = "light", # default
  duration = c("short", "long"), # default
  legend = "include"
)

Aggregated damage curves for "greenpea" crop.

In our example, the damage curves for autumn and winter are equivalent which make them overlap one another. This is why we can not see the color for the “autumn” damage curve. A solution for optimal plotting of these specific damage curves could be done as shown in the chunk below.

HAZARD_AGGREGATE[["week"]] = data.frame(
  min = c(40, 14, 27),
  max = c(13, 26, 39),
  row.names = c("autumn-winter", "spring", "summer")
)
aggregate_damage(
  path,
  hazard_agg = HAZARD_AGGREGATE,
  damage_origin = "total" # default
)

#> Show plot
plot_aggregated_damage(
  path = path,
  damage = "total.aggregate", # default
  culture = "greenpea",
  current = "light", # default
  duration = c("short", "long"), # default
  legend = "include"
)

Aggregated damage curves for "greenpea" crop.

Crop calendars

floodam.agri comes with a default visualisation function called plot_crop_calendar() which creates a plot of the different physiological phases for a set of crops.

#> Show plot
plot_crop_calendar(
  path = path,
  culture = c("greenbean", "greenpea")
)

Calendar of physiological stages for "greenbean" and "greenpea" crops

Learn more

The rest of the vignettes provide more information on several different aspects. Please check:

More vignettes are to come. Stay alert !

References

Agenais, Anne-Laure, Frédéric Grelot, Pauline Brémond, and Katrin Erdlenbruch. 2013. “Dommages Des Inondations Au Secteur Agricole. Guide Méthodologique Et Fonctions Nationales.” Groupe de travail national ACB Inondation. IRSTEA. https://hal.inrae.fr/hal-02600061.
Brémond, Pauline, Anne-Laurence Agenais, Frédéric Grelot, and Claire Richert. 2022. “Process-Based Flood Damage Modelling Relying on Expert Knowledge: A Methodological Contribution Applied to the Agricultural Sector.” Natural Hazards and Earth System Sciences 22 (10): 3385–3412. https://doi.org/10.5194/nhess-22-3385-2022.