Forest Loss Layer

The Forest Loss Layer code creates the forest loss (deforestation and substitution) layer. The input_traza and output_gcbm parameters define the folder where the land-use change data is (Trazabilidad file) and the output data folder respectively.

The layer_traza parameter defines the land use data (Trazabilidad) with the Trazabilidad layer having four fields (T1, T2, T3, T4) with land use data for 4 distinct years. Initially, the LUC shapefile is read and a filter is used to identify polygons that went from non-forest to forest between T1 and T2. The year and name of the disturbance are assigned and a random year is assigned between T1 and T2 for the disturbance.

The important columns are left out, with 2014, 2015 and 2016 years being included and the partial layers bind together. The substitution layer is further developed, from forest to exotic plantations. The polygons that went from forest to plantations between T1 and T2 are filtered and the year and type of substitution are assessed.

sust_t2<- dplyr::filter(
  traza,
  T1 %in% c("0403", "040203", "040202", "040204", "040201", "0402","0304"),
  T2 %in% c("0401"))

sust_t2$year<-year_t2
sust_t2$Perturb<-"Sustitucion"

sust_t2$year<-sample(year_t1:(year_t2),nrow(sust_t2),replace=TRUE)

sust_t2<-sust_t2[,c("year","Perturb")]

The disturbance year is randomized, along with disturbances from T3 to T4. The partial layers are bind together and the forest loss disturbances layer is bound together. We add the project to the WGS84 latitude and longitude and finally write the shapefile.