effSurvArea: Calculation of effective surveyed area

In ggRaver/Lslide: Functions for object-oriented image analysis in landslide science

Calculation of effective surveyed area

Description

This function calculate the effective surveyed area based on viewshed analysis. A valid GRASS GIS session must be initiated before.

Usage

effSurvArea(elev, pts, ID = NULL, maxdist = 1000, do.extend = FALSE,
  path.save = tempdir(), path.temp = tempdir(), method = "bilinear",
  memory = 4096, NAflag = -99999, return.geom = TRUE, quiet = TRUE,
  show.output.on.console = FALSE)

Arguments

elev	RasterLayer containing elevation values
pts	sf containing the points from which the effective surveyed area is estimated.
ID	vector containing names for temporary written data. Vector length must be the same as number of input points. Default: NULL.
maxdist	viewshed distance to analysie. Default: 1000 m
do.extend	extend output to extent of input elev. Default: FALSE
path.save	path to store files. Default: tempdir()
path.temp	path to store tempory files. Default: tempdir()
method	method for extracting elevation values for points. Default: 'bilinear'. Use 'simple' for neares neighbor.
memory	memory used in viewshed computation. GRASS GIS r.viewshed. Default: 4096.
NAflag	replace value for NA (NULL data). Default: -99999.
return.geom	If TRUE geometry is returned by functtion. Default: TRUE.
quiet	do not show comments and state. Default: TRUE
show.output.on.console	show GRASS GIS console output. Default: FALSE

Value

list of RasterLayer of viewshed parameters

Note

• function is taken from Bornaetxea, T., Rossi, M., Marchesini, I., & Alvioli, M. (2018). Effective surveyed area and its role in statistical landslide susceptibility assessments. Natural Hazards and Earth System Sciences, 18(9), 2455-2469.

ggRaver/Lslide documentation built on April 8, 2022, 7:14 a.m.