Test terrain calculations

derive_bathy_variables.R

@@ -0,0 +1,86 @@
+library(akgfmaps)
+library(MultiscaleDTM)
+
+# 2023 Review: Queen case (3x3 neighborhood) for deriving seafloor terrain
+neighbors <- 8
+bpi_w = c(3, 64) # 2023 Review: AI and GOA Radius 3 x 65; EBS radius 3 x 64
+
+x <- terra::rast(here::here("output", "efh_bathy", "efh_bathy_1km.tif"))
+
+# SLOPE using terra ----
+start1 <- Sys.time()
+slope_t <- terra::terrain(x = x, 
+                          v = "slope", 
+                          unit = "degrees", 
+                          neighbors = neighbors)
+
+# MultiscaleDTM: SLOPE (degrees), EASTNESS, AND NORTHNESS
+# Queen case with window = 5
+slope_aspect_dtm <- MultiscaleDTM::SlpAsp(r = x,
+                                          unit = "degrees", # Output units
+                                          w = c(5, 5),
+                                          method = "queen",
+                                          metrics = c("slope", "eastness", "northness"),
+                                          na.rm = TRUE)
+
+# MultiscaleDTM: MEAN CURVATURE, PROFILE CURVATURE, SLOPE
+# Derived from quadratic fit using OLS
+curvature_slope_dtm <- MultiscaleDTM::Qfit(r = x,
+                                           unit = "degrees", # Output units
+                                           w = c(5, 5),
+                                           metrics = c("meanc", "profc",  "qslope"),
+                                           na.rm = TRUE)
+
+# MultiscaleDTM: BATHYMETRIC POSITION INDEX (BPI) ----
+start1 <- Sys.time()
+bpi_dtm <- MultiscaleDTM::BPI(r = x,
+                              w = bpi_w,
+                              unit = "cell", # Units for window
+                              stand = "none",
+                              na.rm = TRUE
+)
+
+end1 <- Sys.time()
+difftime(end1, start1)
+
+
+# Test 100-m resolution
+
+x_100 <- terra::rast(here::here("output", "efh_bathy", "efh_bathy_100m.tif"))
+
+# SLOPE using terra ----
+start2 <- Sys.time()
+slope_t <- terra::terrain(x = x_100, 
+                          v = "slope", 
+                          unit = "degrees", 
+                          neighbors = neighbors)
+
+# MultiscaleDTM: SLOPE (degrees), EASTNESS, AND NORTHNESS
+# Queen case with window = 5
+slope_aspect_dtm <- MultiscaleDTM::SlpAsp(r = x_100,
+                                          unit = "degrees", # Output units
+                                          w = c(5, 5),
+                                          method = "queen",
+                                          metrics = c("slope", "eastness", "northness"),
+                                          na.rm = TRUE)
+
+# MultiscaleDTM: MEAN CURVATURE, PROFILE CURVATURE, SLOPE
+# Derived from quadratic fit using OLS
+curvature_slope_dtm <- MultiscaleDTM::Qfit(r = x_100,
+                                           unit = "degrees", # Output units
+                                           w = c(5, 5),
+                                           metrics = c("meanc", "profc",  "qslope"),
+                                           na.rm = TRUE)
+diff(Sys.time(), start2)
+
+# MultiscaleDTM: BATHYMETRIC POSITION INDEX (BPI) ----
+start1 <- Sys.time()
+bpi_dtm <- MultiscaleDTM::BPI(r = x_100,
+                              w = bpi_w,
+                              unit = "cell", # Units for window
+                              stand = "none",
+                              na.rm = TRUE
+)
+
+end2 <- Sys.time()
+difftime(end2, start2)

make_efh_bathymetry.R

@@ -2,6 +2,9 @@ library(akgfmaps)
 library(reticulate)
 
 
+dir.create(here::here("data", "efh_bathy"), recursive = TRUE)
+dir.create(here::here("output", "efh_bathy"), recursive = TRUE)
+
 # Transform GEBCO Z coordinates to match Alaska bathymetry (negative is up)
 gebco <- terra::rast(here::here("data", "gebco_2023_n67.0_s54.0_w-175.0_e-154.0.tif"))
 gebco <- gebco * -1
@@ -23,13 +26,16 @@ efh_bathy_trim <- terra::rast(here::here("data", "efh_bathy", "efh_bathy_100.tif
 
 names(efh_bathy_trim) <- "depth"
 
-terra::writeRaster(efh_bathy_trim, here::here("data", "efh_bathy", "efh_bathy_100m.tif"), overwrite = TRUE)
+terra::writeRaster(efh_bathy_trim, here::here("output", "efh_bathy", "efh_bathy_100m.tif"), overwrite = TRUE)
 
 
 # Resample the 100 m resolution grid to 1 km
 efh_100m <- terra::rast(here::here("data", "efh_bathy", "efh_bathy_100m.tif"))
 
 efh_1km <- terra::aggregate(efh_100m, fact = 10, fun = "mean")
 
-terra::writeRaster(efh_1km, here::here("data", "efh_bathy", "efh_1km.tif"), overwrite = TRUE)
+terra::writeRaster(efh_1km, here::here("output", "efh_bathy", "efh_bathy_1km.tif"), overwrite = TRUE)
+
+
+