tool function to extract transitions between categories from a land data set with at least 2 time steps. The approach is rather simplistic by assuming that expansion happens proportionally in all affected classes (equal preference of transitions across all categories).
Arguments
- x
magpie data set containing land data with at least two time steps to extract net transitions from
- gross
either boolean or a magpie object containing bidirectional transition shares relative to the area of the involved land pools (transition divided by the area of the land pool in the "from" sub dimension). If set to FALSE only net transitions will be returned. If set to TRUE an internal gross transition estimate based on average gross transitions in LUH2 in the period from 1995 to 2015 will be used.
Details
In addition to the net effect it can also estimate gross transition. For that purpose a reference data set containing bidirectional transition shares must be provided.
If the time step length is longer than 1 year the returned object contains reference years for each period which can be repeated to retrieve the full transition between two time periods, e.g. if you provide two time steps 2000 and 2005 the return value will be the transition for year 2001. Repeating the same transition also in 2002, 2003, 2004 and 2005 will give the full transition from 2000 to 2005.