Convert bathymetry raster to hypsograph — bathy_to

This function converts a bathymetry raster to a hypsograph, which is a data.frame with the area of the lake at different depths. The function takes a bathymetry raster as input and returns a data frame with the depth and area at each depth.

Usage

bathy_to_hypso(bathy_raster, surface = 0, depths = NULL)

Arguments

bathy_raster: SpatRaster object with bathymetry depths (negative values).
surface: numeric. The surface elevation of the lake. Default is 0.
depths: numeric. The depths at which to calculate the area. If a single numeric value is provided, the function will calculate the area at each depth from the surface to the minimum depth of the bathymetry raster at intervals of the provided value. If a vector of numeric values is provided, the function will calculate the area at each depth specified in the vector. if NULL, the function will use the default depths from the model layer structure. Default is NULL.

Value

data.frame

Examples

shoreline <- readRDS(system.file("extdata/rotoma_shoreline.rds",
package = "bathytools"))
depth_points <- readRDS(system.file("extdata/depth_points.rds",
package = "bathytools"))
bathy_raster <- rasterise_bathy(shoreline = shoreline,
depth_points = depth_points, crs = 2193)
#> Generating depth points... [2025-08-25 02:34:17]
#> Finished! [2025-08-25 02:34:18]
#> Interpolating to raster... [2025-08-25 02:34:18]
#> Adjusting depths >= 0 to  -0.82 m
#> Finished! [2025-08-25 02:34:33]

hyps <- bathy_to_hypso(bathy_raster = bathy_raster)