Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.
Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
This modules provides information about the importance of single patches for maintaining the connectivity of individual fragments derived of a landcover classification. Unlike r.pi.energy.pr this module provides information about the differences in time from emigration to immigration. The individual based dispersal model results are based on the step length and range, the perception distance and the attractivity to move towards patches.
The patch relevance concerning connectivity are based on patches of the
landclass96 raster class 5 amd the time (amount of steps) from
emigration to immigration is computed. The step length is set to 5
pixel, the output statistics are set to average time and
variance of searchtime. For each patch 1000 individuals were
released and the model stopped when at least 80% of all individuals
sucessfully immigrated:
r.pi.searchtime.pr input=landclass96 output=searchtime_iter1 keyval=5 step_length=5 stats=average,variance percent=80 n=1000 dif_stats=average
r.pi.searchtime.pr input=landclass96 output=searchtime_iter1 keyval=5 step_length=5 stats=average,variance percent=80 n=1000 dif_stats=average perception=10
r.pi.searchtime.pr input=landclass96 output=searchtime_iter1 keyval=5 step_length=5 stats=average,variance percent=80 n=1000 dif_stats=average multiplicator=10
r.pi.searchtime.pr input=landclass96 output=searchtime_iter1 keyval=5 step_length=5 stats=average,variance percent=80 n=1000 dif_stats=average out_freq=10
r.pi.searchtime.pr input=landclass96 output=searchtime1 keyval=5 step_length=5 stats=average,variance percent=80 n=1000 dif_stats=average out_immi=immi_counts
# it is assumed that our species is a forest species and cannot move # through water, hence a cost of 100, does not like urban areas # (class: 6, cost: 10) but can disperse through shrubland (class 4, # cost=1) better than through grassland (class 3, cost: 2): r.mapcalc "suit_raster = if(landclass96==5,1,if(landclass96 == 1, 10, if (landclass96==3,2, if(landclass96==4,1,if(landclass96==6,100)))))" r.pi.searchtime.pr input=landclass96 output=searchtime1 keyval=5 step_length=5 stats=average,variance percent=80 n=1000 dif_stats=average suitability=suit_raster
Port to GRASS GIS 7: Markus Metz
Available at: r.pi.searchtime.pr source code (history)
Latest change: Monday Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55
Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.
Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
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