toolHarmonizeAbsoluteChanges

Tool function for creating a harmonized data set by applying the absolute changes of the input data to the target data: up to the harmonization year the target data is used, afterwards the difference of the input data to the input data of the harmonization year is added to the target data of the harmonization year.

Usage

toolHarmonizeAbsoluteChanges(
  xInput,
  xTarget,
  harmonizationPeriod,
  constantTotal
)

Arguments

xInput

input data as magpie object

xTarget

target data as magpie object

harmonizationPeriod

Two identical integer values, the year the absolute changes of the input data are applied to, must be present in both input and target data

constantTotal

TRUE if the total area of each cell is constant over time

Value

harmonized data set as magpie object with data from target for years up to and including the harmonization year and absolute changes from input relative to the harmonization year afterwards

Details

Negative values are handled within groups of related categories (forest & other land; all cropland types; pasture & rangeland), so that they are compensated by the other categories of the group. For crops, negative values are first compensated by the corresponding rainfed/irrigated twin of the same crop. Crop categories without their twin are compensated by the whole group. Groups with a negative total area are set to zero. Afterwards, if any negatives remain, all categories except urban are scaled down to keep the total area constant.

primf and primn cannot regrow, so if they were scaled down to compensate that would persist in all later timesteps (toolReplaceExpansion caps prim areas at previous timestep). Hence they are only scaled down once all other variables in their group were scaled down to zero first. This group compensation and constant total area applies only to data whose total area is constant (constantTotal = TRUE). For constantTotal = FALSE data negative values are simply clamped to zero.

Author

Pascal Sauer