DESCRIPTION
v.out.marxan is a python script prepare a vecotr planning grid file and create marxan input files.
Marxan output can be read back into GRASS for display with v.in.marxan.
NOTES
Use of the DOS output format will create a second file with '.dos' appended to the output file name.
Consistent specification of the Planning Unit Key field is necessary in all Marxan scripts to ensure a working set of ouptut files.
All GRASS Marxan modules require Python, PostgreSQL 8.x or higher and are intended for use with Marxan version 1.8.10.
One of the options for output is the scaling of boundary and species variables to ranges between 0 and 1. Since the
objective function of Marxan is sum of the planning unit cost plus the sum of the boundary cost * the boundary length
modifier plus the sum of species penalty factors, it is desirable that all of these be kept within the same order
of magnitude. The scaling function for data outputs is designed to address this.
The second potentially useful feature is in the calculation of the boundary length. A Calculated option is provided
that multiplies the actual length in map units by the specified attribute of the adjacent planning unit. In this case
the user needs to specify whether the greater or lesser value will be applied in all cases where they differ. This calculated
value is then scaled to range from 0 to 1. This allows for using attributes attached to each planning unit to
define the relative merit of joining them together. This might be particularly useful in cases where certain habitats
have synergetic effects and others do not work well together.
These brief notes do not in any constitute a outline of Marxan's capabilities or provide guidance to appropriate use.
For this please familiarize yourself with the user manual and good practices handbook found on the Marxan home page.
SEE ALSO
v.out.marxan,
v.mkhexgrid,
Marxan Home Page
AUTHOR
Trevor Wiens
REFERENCES
Ball, I.R., and H.P. Possingham, 2000. MARXAN (V1.8.2): Marine Reserve Design Using Spatially Explicit Annealing, a Manual.
Game, E.T. and H.S. Grantham, 2008. Marxan User Manual: For Marxan version 1.8.10. University of Queensland, St. Lucia, Queensland, Australia, and Pacific Marine Analysis and Research Association, Vancouver, British Columbia, Canada.
Possingham, H. P., I. R. Ball and S. Andelman (2000) Mathematical methods for identifying representative reserve networks. In: S. Ferson and M. Burgman (eds) Quantitative methods for conservation biology. Springer-Verlag, New York, pp. 291-305.
Ardron, J. H.P. Possingham and C.J. Klein (Eds.),Version 2, 2010. Marxan good practices handbook. University of Queensland, St. Lucia, Queensland, Australia, and Pacific Marine Analysis and Research Association, Vancouver, British Columbia, Canada.
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