CreateGRiwrm {airGRiwrm}

Generation of a network description containing all hydraulic nodes and the description of their connections

Description

Generation of a network description containing all hydraulic nodes and the description of their connections

Usage

CreateGRiwrm(
  db,
  cols = list(id = "id", down = "down", length = "length", model = "model", area =
    "area"),
  keep_all = FALSE
)

Arguments

db

data.frame description of the network (See details)

cols

list or vector columns of db. By default, mandatory column names are: id, down, length. Other names can be handled with a named list or vector containing items defined as "required name" = "column name in db"

keep_all

logical indicating if all columns of db should be kept or if only columns defined in cols should be kept

Details

db is a data.frame which at least contains in its columns:

• a node identifier (column id),

• the identifier and the hydraulic distance to the downstream node (character columns down and numeric columns length in km). The last downstream node should have fields down and length set to NA,

• the area of the basin (numeric column area in km2)

• the hydrological model to use if necessary (character column model) (NA for using observed flow instead of a runoff model output)

Value

data.frame of class GRiwrm describing the airGR semi-distributed model network, with each line corresponding to a location on the river network and with the following columns:

• id (character): node identifier

• down (character): identifier of the node downstream of the current node (NA for the most downstream node)

• length (numeric): hydraulic distance to the downstream node in km (NA for the most downstream node)

• area (numeric): total area of the basin starting from the current node location in km2

• model (character): hydrological model to use if necessary (NA for using observed flow instead of a runoff model output)

Examples

###################################################################
# Run the `airGR::RunModel_Lag` example in the GRiwrm fashion way #
# Simulation of a reservoir with a purpose of low-flow mitigation #
###################################################################

## ---- preparation of the InputsModel object

## loading package and catchment data
library(airGRiwrm)
data(L0123001)

## ---- specifications of the reservoir

## the reservoir withdraws 1 m3/s when it's possible considering the flow observed in the basin
Qupstream <- matrix(-sapply(BasinObs$Qls / 1000 - 1, function(x) {
  min(1, max(0, x, na.rm = TRUE))
}), ncol = 1)

## except between July and September when the reservoir releases 3 m3/s for low-flow mitigation
month <- as.numeric(format(BasinObs$DatesR, "%m"))
Qupstream[month >= 7 & month <= 9] <- 3
Qupstream <- Qupstream * 86400 ## Conversion in m3/day

## the reservoir is not an upstream subcachment: its areas is NA
BasinAreas <- c(NA, BasinInfo$BasinArea)

## delay time between the reservoir and the catchment outlet is 2 days and the distance is 150 km
LengthHydro <- 150
## with a delay of 2 days for 150 km, the flow velocity is 75 km per day
Velocity <- (LengthHydro * 1e3 / 2) / (24 * 60 * 60) ## Conversion km/day -> m/s

# This example is a network of 2 nodes which can be describe like this:
db <- data.frame(id = c("Reservoir", "GaugingDown"),
                 length = c(LengthHydro, NA),
                 down = c("GaugingDown", NA),
                 area = c(NA, BasinInfo$BasinArea),
                 model = c(NA, "RunModel_GR4J"),
                 stringsAsFactors = FALSE)

# Create GRiwrm object from the data.frame
griwrm <- CreateGRiwrm(db)
str(griwrm)

# Formatting observations for the hydrological models
# Each input data should be a matrix or a data.frame with the good id in the name of the column
Precip <- matrix(BasinObs$P, ncol = 1)
colnames(Precip) <- "GaugingDown"
PotEvap <- matrix(BasinObs$E, ncol = 1)
colnames(PotEvap) <- "GaugingDown"

# Observed flows contain flows that are directly injected in the model
Qobs = matrix(Qupstream, ncol = 1)
colnames(Qobs) <- "Reservoir"

# Creation of the GRiwrmInputsModel object (= a named list of InputsModel objects)
InputsModels <- CreateInputsModel(griwrm,
                            DatesR = BasinObs$DatesR,
                            Precip = Precip,
                            PotEvap = PotEvap,
                            Qobs = Qobs)
str(InputsModels)

## run period selection
Ind_Run <- seq(which(format(BasinObs$DatesR, format = "%Y-%m-%d")=="1990-01-01"),
               which(format(BasinObs$DatesR, format = "%Y-%m-%d")=="1999-12-31"))

# Creation of the GriwmRunOptions object
RunOptions <- CreateRunOptions(InputsModels,
                                IndPeriod_Run = Ind_Run)
str(RunOptions)

# Parameters of the SD models should be encapsulated in a named list
ParamGR4J <- c(X1 = 257.238, X2 = 1.012, X3 = 88.235, X4 = 2.208)
Param <- list(`GaugingDown` = c(Velocity, ParamGR4J))

# RunModel for the whole network
OutputsModels <- RunModel(InputsModels,
                          RunOptions = RunOptions,
                          Param = Param)
str(OutputsModels)

# Compare Simulation with reservoir and observation of natural flow
plot(OutputsModels, data.frame(GaugingDown = BasinObs$Qmm[Ind_Run]))