Tropical Moist Forests product

Code

library(terra)
library(sf)
library(ggplot2)
library(knitr)

This product, developed by the European Commission’s Joint Research Centre, classifies forest areas and detects annual changes, including deforestation and forest degradation. Based on Landsat images, it provides data from 1990 to 2024 at a resolution of 30 metres.

Code

# download tmf - annual change for luzon between 1990 and 2024
dir_tmf <- "data/tmf"
if (!dir.exists(dir_tmf)) dir.create(dir_tmf)
for (yr in 1990:2024) {
  file <- paste0(
    dir_tmf, "/JRC_TMF_AnnualChange_v1_", yr,
    "_ASI_ID76_N20_E120.tif"
  )
  if (!file.exists(file)) {
    paste0(
      "https://ies-ows.jrc.ec.europa.eu/iforce/tmf_v1/download.py?",
      "type=tile&dataset=AnnualChange_", yr, "&lat=N20&lon=E120"
    ) |>
      download.file(file, mode = "wb")
  }
}

Code

tmf_files <- list.files(dir_tmf, pattern = "AnnualChange", full.names = TRUE)
years <- gregexpr("[0-9]+", tmf_files) |>
  regmatches(x = tmf_files) |>
  lapply(as.numeric) |>
  lapply(function(i) i[i > 1900]) |>
  unlist()
data <- data.frame(
  year = years,
  Undisturbed = -1,
  Degraded = -1,
  Deforested = -1,
  Regrowth = -1,
  Water = -1,
  Other = -1
)
area <- list.files("data/umrbpl/", full.names = TRUE, pattern = "shp$") |>
  read_sf() |>
  st_transform(crs = "EPSG:4326")
tmf <- tmf_files |>
  rast() |>
  crop(area) |>
  mask(area) |>
  lapply(function(r) {
    levels(r) <- names(data)
    r
  }) |>
  rast()
names(tmf) <- years

for (i in seq_len(dim(tmf)[3])) {
  for (c in 1:6) {
    cat_mask <- (tmf[[i]] == c)
    n_pixels <- global(cat_mask, fun = "sum", na.rm = TRUE)$sum
    surface_ha <- n_pixels * 30 * 30 / 10000
    data[i, c + 1] <- surface_ha
  }
}

Maps

Code

plot(c(
  tmf[[which(grepl(2010, names(tmf)))]],
  tmf[[which(grepl(2024, names(tmf)))]]
), col = c("darkgreen", "orange", "red", "green", "lightblue", "grey"))

Changes in forest area between 1990 and 2024

Code

ggplot(data, aes(x = year)) +
  geom_line(aes(y = Degraded, color = "Degraded"), size = 0.9) +
  geom_line(aes(y = Deforested, color = "Deforested"), size = 0.9) +
  geom_line(aes(y = Regrowth, color = "Regrowth"), size = 0.9) +
  scale_color_manual(name = "", values = c(
    "Degraded" = "orange",
    "Deforested" = "red",
    "Regrowth" = "green"
  )) +
  labs(title = "TMF changes from 1990 to 2024", x = "Year", y = "Surface (Ha)")