Description Usage Arguments Details Value Author(s) References Examples
The phylogenetic spreading of the tibetan carabidae seems to be correlated to valley linkage and available humidity. Long term humidity is bound to precipitation and morphometry. It is obvious that the estimation of spreeading speed and range is in no case a simple euclidian one. runBeetle provides a first better estimation using a cost or friction analysis assuming that the spread is following natural lines of wetness e.g. valleys, humidity gradients...whatever I'am not a beetle ask the beetle beetle guy.
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rootDir |
project directory |
workingDir |
working directory |
inputData |
location data containing obligatory the cols lon,lat and optional a code col. The format has to be a data frame see example. |
costType |
used if internalCost = TRUE. default is "tci" you can choose "tci" "dem.filled" or "accu" see details for more information |
internalCost |
default = TRUE switches to external provided GTiff file wich has to be named cost.tifx |
dump |
default = FALSE if TRUE export r.terraflow products to GTiff |
usedump |
default = FALSE instead of running r.terraflow again use products products to GTiff |
externalCostRaster |
default = NULL you may provide a GTiff file with the name cost.tif NOTE you have to set internalCost = FALSE |
The core of the analysis is an isotropic/anisotropic least cost path
calculation. By default the cost surface is assumed to be a local derivate
of the morphometry with respect to the potential soil humidity. A perfect
approch to derive such information is the use of a Digital Elevation Model
DEM and some corresponding derivates as the Topographic Convergence Index.
If you choose "tci" (default) the cost surface provides an estimation of
rainwater runoff availability to plants based on specific catchment area (A)
and local slope (b) such that TCI = ln(A/tan b) (Beven & Kirkby, 1979). This
seems be pretty straightforward and fairly suitable for the beetles
"behaviour.
If you chosse "accu" a typical accumulation cost grid from the original DEM
will be used
If you choose "dem.filled" a typical accumulation cost grid from the
hydrologically corrected DEM will be used
For the r.walk algorithm the non accumulated data is used.
runBeetle returns:
(a) a dataframe with the (a) euclidian distances, (b) cost distance (isotropic cost surface) and (c) the walk distance (anisotropic cost surface)
Chris Reudenbach
Maintainer: Chris REudenbach reudenbach@uni-marburg.de
Schmidt, J., B<c3><b6>hner, J., Brandl, R. & Opgenoorth, L. (in review): Mass elevation and lee effect override latitudinal effects in determining the distribution ranges of species: Ground beetles from the Himalaya-Tibet Orogen. <e2><80><93> PLoS ONE.
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#### NOTE: You obligatory need GRASS70
library(doParallel)
library(foreach)
library(raster)
library(sp)
library(gdalUtils)
library(rgdal)
### NOTE: the area is specifified and automatically downloaded (SRTM) by the input data extent plus a "zone"
### read a csv file
fn<-system.file("bug.csv", package="biomix")
beetleLocs<-read.csv2(fn,header = TRUE,sep = ',',dec = '.',stringsAsFactors=FALSE)
### use some arbitrary locations from scratch
beetleLocs <- as.list(c("86.83", "28.20", "100","84.58", "28.67", "200" ,"83.87", "28.80", "300"))
beetleLocs <- data.frame(matrix(as.numeric(unlist(beetleLocs)), nrow=3, byrow=T),stringsAsFactors=FALSE)
colnames(beetleLocs)<-c("lon","lat","code")
beetleDist<-runBeetle(rootDir = "/home/creu/proj/beetle" ,inputData = beetleLocs, usedump=TRUE, walk=TRUE)
## End(Not run)
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