Creating Bioclimatic Variables Using DIVA GIS

[logan sholar]

Hello All,

This is not a direct Maxent question, but more of a preparing data for
Maxent question.

I am in the process of creating the 19 Bioclimatic variables as
described on the WorldClim website with HADCM3 (30s) A2a 2050 Tmin,
Tmax and Prec datasets by using DIVA GIS. I am at the point at which I
need to create .CLM files from .GRD files (Data>Climate>Make CLM files
- in DIVA GIS). I am following the guidelines set forth in a paper by
Ramirez (Ramirez_2009_tutorial_bcvars_creation.pdf) and this is step 6
in that paper.

I get to step 6e and click "Files", but nothing happens. Up to this
point, the prompt box has been filled in correctly for every blank as
described in steps 6a-d. When the "Files" button is clicked, three
selected files boxes should be filled in with the names of the 12 .GRD
files for each dataset. This is not happening.

Can anyone tell me why this process may not be running?

I have included the alt.grd file so the altitude mask will be applied,
and all the .GRD files have been clipped to a very small rectangle in
Southern California, so the 30s data should not be too large.

Any help would be greatly appreciated, I'm soooo close!

Thank you,

Logan

[Alessandro]

I know this is an extremely old thread, but i am struggling with the exact same problem and it appears that no one answered to this topic at the time.
I have the same issue so i might as well up this very old topic, hoping that someone could solve it now.
It's not really part of Maxent, but its one of the basic steps required to use it.
Anybody have any ideas?

[kristi...@gmail.com]

HI Allessandro,

 

I have had this same problem.  I think it is an issue with DIVA_GIS.  I sturggled with this problem for a week and then all of a sudden DIVA I clicked Files and they were there.  I don't know what version I was working with.  I think you should try to re-install DIVA.  OR switch to another version. 

[Kris]

Hi Matthew

 

Could I use the same code if I want to make bioclim variables for a decade?  So I have 36 files per year (12 tmax, 12 tmin, 12 prec).  Should I combine say prec_1 for 1960, 1961 and so on until 1969 to get one file that has all precipitation for one year and call that Prec_1.  Or do I make individual bioclim variables for each year and then merge those together?

 

Any help would so be appreciated.

 

Kris
On Monday, April 22, 2013 11:52:34 AM UTC-5, Matthew B wrote:

Hi Logan, 

Sorry this is a late reply, but for anyone else over looking this thread please pay attention to the EXACT files names. 

You need to combine all your grd files into one folder. When you download the original tiles and convert bil to grd the standard naming convention is '(variable)(month)_(tile)' ie bio3_11.grd; tmin6_11.grd ect.. In the file prefix boxes rename the prefixs to "tmin_', 'tmax_' and 'prec_' then rename all of your files to match this prefix (ie. tmin5_11,  would become tmin_5) (variable)_(month).grd . Leave altitude as just alt.grd. 

If you need to combine multiple tiles you can use merge tiles in Diva gis, click on grid -> merge. If you want to merge many grid files ie. 3 worldclim tiles with 19 bioclim variables follow the steps outlined in this thread:

https://groups.google.com/forum/#!msg/maxent/045l4NYb4JI/c4uXWKYYC5YJ (or follow steps in the R-raster package)

[Matthew B]

Making the 19 Bioclimatic grids from monthly climate grids:

 

It is my understanding that there are at least ways that this can be accomplished

 

1.        In R using the biovars function in the dismo package

2.        In ArcGIS using an AML scrit via ArcInfo

3.        In DIVA GIS using the climate map option

4.        Other methods(?) …

 

1.)      The method in R is very straightforward, simple review the help page for the biovars function in the dismo package http://www.inside-r.org/packages/cran/dismo/docs/biovars The limitation to this method is that the biovars function seems to just freeze up for me when I am trying to make some large raster files. I have only had success with biovars with very small files.

2.)      ArcGIS is another option, however; ever with Arcmap 10.X I still would need to pay extra $$$ to use ArcInfo from a home computer.

3.)      DIVGIS seems to be the simplest and more straightforward option for entry level modelers & students.

a.        Install DIVA GIS

b.       Gather whatever monthly climate data you have into a single folder (you need monthly precipitation; minimum temperature and maximum temperature).

c.        Make climate files from monthly grids (Data > Climate > Make CLM files *search google for a tutorial on this part if needed.

d.       Select your new climate files to be used in DIVA GIS (tools > options > climate *again, search google for a tutorial on this step if needed.

e.        MAKE 19 BIOCLIMATE GRIDS: Data > Climate > Map > draw rectangle (select area of interest) > Output (change to bioclim & select ‘all’) > set destination folder & create your 19 bioclimatic grids from the monthly data. 

[shawkat sohel]

Hi All,

I am also facing the same problem. I tried to prepare my climatic data for the prefix boxes as you mention ie.  tmin_5 in this format. I am following Ramirez_2009_tutorial_bcvars_creation.pdf for data preparation. But When I click the file option that it says 'alt/mask file doesn't exist'. I am attaching you my data for your better understanding. Please any suggestion will be highly appreciated. 

Thanks and will be waiting for your kind response.