ch_wbt_flow_direction: Creates flow direction grid file

In CSHS-hydRology/CSHShydRology: Canadian Hydrological Analyses

Creates flow direction grid file

Description

Creates flow direction grid file

Usage

ch_wbt_flow_direction(fn_dem_ns, fn_flowdir, return_raster = TRUE)

Arguments

fn_dem_ns	File name of dem with sinks removed.
fn_flowdir	File name for flow direction grid to be created.
return_raster	Should a raster object be returned?

Value

If return_raster = TRUE (the default), the flow direction grid will be returned as a raster object, in addition to being written to fn_flowdir. If return_raster = FALSE, the output file will still be created but a NULL value is returned.

Author(s)

Dan Moore

Examples

# Not tested automatically as requires installation of Whitebox
library(raster)
test_raster <- ch_volcano_raster()
dem_raster_file <- tempfile(fileext = c(".tif"))
no_sink_raster_file <- tempfile("no_sinks", fileext = c(".tif"))

# write test raster to file
writeRaster(test_raster, dem_raster_file, format = "GTiff")

# remove sinks
removed_sinks <- ch_wbt_removesinks(dem_raster_file, no_sink_raster_file, method = "fill")

# get flow directions
flow_dir_file <- tempfile("flow_dir", fileext = c(".tif"))
flow_dir <- ch_wbt_flow_direction(no_sink_raster_file, flow_dir_file)
plot(flow_dir)

CSHS-hydRology/CSHShydRology documentation built on Aug. 18, 2022, 4:44 p.m.