elev_to_terrain_analysis: Calculate derivatives from the Terrain Analysis module

In loreabad6/terrain: Utility Functions for Terrain Derivatives Calculations

Calculate derivatives from the Terrain Analysis module

Description

Calculate derivatives from the Terrain Analysis module

Usage

elev_to_terrain_analysis(
  elev_sgrd,
  out_dir,
  prefix = "",
  envir,
  ...,
  lsfct = FALSE,
  flow = FALSE,
  spcar = FALSE,
  twidx = FALSE
)

Arguments

elev_sgrd	input, elevation raster data in SAGA format, can be created with elev_to_sgrd()
out_dir	output directory
prefix	character prefix for output filenames
envir	environment to get SAGA installation, can be set with init_saga()
...	ignored, check help page for possible outputs
lsfct	LS Factor: L is the slope length factor, representing the effect of slope length on erosion. It is the ratio of soil loss from the field slope length to that from a 72.6-foot (22.1-meter) length on the same soil type and gradient. Slope length is the distance from the origin of overland flow along its flow path to the location of either concentrated flow or deposition. S is the slope steepness. Represents the effect of slope steepness on erosion. Soil loss increases more rapidly with slope steepness than it does with slope length. L factor and S factor are usually considered together. LS factors = the slope length factor L computes the effect of slope length on erosion and the slope steepness factor S computes the effect of slope steepness on erosion. Values of both L and S equal 1 for the unit plot conditions of 72.6 ft length and 9 percent steepness. Values of L and S are relative and represent how erodible the particular slope length and steepness is relative to the 72.6 ft long, 9% steep unit plot. Thus some values of L and S are less than 1 and some values are greater than 1. Boolean, defaults to FALSE
spcar, flow	Specific Catchment Area and Flow Accumulation: SCA is A parameter of the tendency to receive water. The contributing area (also known as basin area, upslope area, or flow accumulation) deter-mines the size of the upslope area (derived by the number of cells) draining into a cell. Boolean, defaults to FALSE When TRUE, then flow should also be TRUE
twidx	Topographic Wetness Index: Describes the tendency of an area to accumulate water. Areas prone to water accumulation (large contributing drainage areas) and characterized by low slope angle will be linked to high TWI values. On the other hand, well-drained dry areas (steep slopes) are associated to low TWI values. Boolean, defaults to FALSE

References

Mattivi, P., Franci, F., Lambertini, A. et al. TWI computation: a comparison of different open source GISs. Open geospatial data, softw. stand. 4, 6 (2019). https://doi.org/10.1186/s40965-019-0066-y

loreabad6/terrain documentation built on July 6, 2023, 6:44 a.m.