Calculates the discharge and constituent loads (e.g. nitrogen, phosphorus, carbon) entering the lake via its inflows, expressed as both totals over the simulation period and annual averages. Useful for getting a quick overview of how much water and nutrient mass is being delivered to the lake, and by which inflow.
Arguments
- aeme
Aeme object.
- inflow_vars
character; vector of AEME inflow concentration variable names to calculate loads for (e.g.
c("NIT_tn", "PHS_tp")). IfNULL(default), all recognised mass-concentration variables present in the inflow data are used.- by_inflow
logical; if
TRUE(default), totals are broken down byinflow_idas well as summed across all inflows (labelled"all"). IfFALSE, only the combined total across all inflows is returned.
Value
A data frame with columns:
inflow_id: the inflow identifier, or"all"for the sum across all inflows.var_aeme: variable name ("HYD_flow"for discharge, or the AEME concentration variable name for a load).name_text: human-readable variable name.metric:"discharge"or"load".unit: unit of thetotalandannual_averagecolumns ("m3"for discharge,"kg"for loads).total: total discharge/load summed over the full inflow record.annual_average:totaldivided by the number of years spanned by the inflow record.n_years: number of years spanned by the inflow record, used to calculateannual_average.
Details
Discharge is summed directly from the HYD_flow column (m3/day).
Constituent loads are calculated as HYD_flow * concentration for
each recognised mass-concentration variable (units g/m^3 in
key_naming, e.g. NIT_tn, NIT_amm, PHS_tp,
PHS_frp, CAR_doc, CAR_poc) present in the inflow data,
summed over time and converted from g to kg.
Examples
if (FALSE) { # \dontrun{
summarise_loads(aeme)
summarise_loads(aeme, inflow_vars = c("NIT_tn", "PHS_tp"))
} # }