Land cover and soil layers for prediction in MAXENT

[Mahmoud Saleh Abdel-Dayem]

Hi
I am trying to predict the distribution of sand fly species using 19
bioclim layers and elevation and slope in Maxent; but I couldn't add
the vegetation or land cover to the model, each time Maxent's message
tell me that that land cover or soil layers are with different cell
size, number of columns and rows. So, Please any one has an idea or
way to make soil and land cover layers with the sam cell size, number
of rows and columns like 19 bioclim layers.

Cheer
Mahmoud

[Alvar Carranza]

Mahmoud, one possible solution is to convert the veg raster to point
(Raster to point in Conversion tools) and then again point to raster,
but indicating the same exent and cell size of your bioclim layers

best

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--
Msc. Alvar Carranza

UNDECIMAR
Facultad de Ciencias
Universidad de la República
Iguá 4225

Área Biodiversidad y Conservación
Museo Nacional de Historia Natural
Casilla de Correo 399
Montevideo, Uruguay

http://alvar.carranza.googlepages.com

[Husam El Alqamy]

Dear Dr. Mahmoud
It might be that be your data is OK but slight difference in cell size is
making the problem. Have a look on the ASC flies, they should have the same
header data (number of columns, number of rows and cell size) ex:
ncols 1464
nrows 1159
xllcorner 24.700010675937
yllcorner 21.991670942865
cellsize 0.0083333337679505
if the ncols and nrows are the same for all the asc files this is ok. The
problem then is your cell size. Just go in using notepad or a text editor
and change the cell size into the same number.
Ex if your situation is something like this
ncols 1464
nrows 1159
xllcorner 24.700010675937
yllcorner 21.991670942865
cellsize 0.0083333337679505 and

ncols 1464
nrows 1159
xllcorner 24.700010675937
yllcorner 21.991670942865
cellsize 0.0083333 then change all into one common cell size, any
one of the two would do it. This is often happen when you use ArcGIS to clip
the raster using a polygon but you don't specify the cell size and the snap
to raster in the environment section. Hope it works.

Husam El Alqamy, B.Sc., M.Phil.
Protected Area Coordinator,
Biodiversity Management Sector, BMS
Environmental Agency - Abu Dhabi
Antelope Specialist Group - ASG, IUCN.

Cheer
Mahmoud

--

[Navinder Singh]

Mahmoud,
Set your extent in spatial analyst to a raster u want to use as the base.
Keeping this as extent u can then clip all others to this extent.
This is done by-
Spatial analyst>options>cell size (what you wish)>extent layer (specify here)> set mask
open raster calculator
E.g elevation=elevation (this will Now be clipped to your new extent)
Do the same for all other layers.
Hope this helps,
Cheers,
Navinder

Sent from my iPad

[Mahmoud Saleh Abdel-Dayem]

Dear Husam

Thanks for your help. I am really happy to meet you in this group. I will try your sugestions to solve my problems.

--
with my best regards

Mahmoud Saleh Abdel-Dayem (Ph.D)
Entomology Department
Faculty of Sciences
Cairo University
Giza, Egypt
Tel. Home: 002025644773
Tel. Office: 002025676823
Mobil: 0020106042615

[Mahmoud Saleh Abdel-Dayem]

Thanks Navinder for your help

I will try your suggestion

Best wishes

Mahmoud

[Mahmoud Saleh Abdel-Dayem]

Thank you Alvar for your help

I will try your way

Wishes

Mahmoud

[Mahmoud Saleh Abdel-Dayem]

Hi Alvar
I tried your way, but I faced the same problem with Maxent

On Oct 19, 9:19 pm, Alvar Carranza <alvar.carra...@gmail.com> wrote:
> Mahmoud, one possible solution is to convert the veg raster to point
> (Raster to point in Conversion tools) and then again point to raster,
> but indicating the same exent and cell size of your bioclim layers
>
> best
>
> On Tue, Oct 19, 2010 at 7:23 AM, Mahmoud Saleh Abdel-Dayem
>
>
>
>
>
> <msabdelda...@gmail.com> wrote:
> > Hi
> > I am trying to predict the distribution of sand fly species using 19
> > bioclim layers and elevation and slope in Maxent; but I couldn't add
> > the vegetation or land cover to the model, each time Maxent's message
> > tell me that that land cover or soil layers are with different cell
> > size, number of columns and rows. So, Please any one has an idea or
> > way to make soil and land cover layers with the sam cell size, number
> > of rows and columns like 19 bioclim layers.
>
> > Cheer
> > Mahmoud
>
> > --
> > You received this message because you are subscribed to the Google Groups "Maxent" group.
> > To post to this group, send email to max...@googlegroups.com.
> > To unsubscribe from this group, send email to maxent+un...@googlegroups.com.

> > For more options, visit this group athttp://groups.google.com/group/maxent?hl=en.

>
> --
> Msc. Alvar Carranza
>
> UNDECIMAR
> Facultad de Ciencias
> Universidad de la República
> Iguá 4225
>
> Área Biodiversidad y Conservación
> Museo Nacional de Historia Natural
> Casilla de Correo 399
> Montevideo, Uruguay
>

> http://alvar.carranza.googlepages.com- Hide quoted text -
>
> - Show quoted text -

[Mahmoud Saleh Abdel-Dayem]

Dear Husam
I changed the ascii file for vegetation to be the same in bioclim
layers; but still the same message from the Maxent.

> For more options, visit this group athttp://groups.google.com/group/maxent?hl=en.- Hide quoted text -

[Mahmoud Saleh Abdel-Dayem]

Hi Navinder
I still have the same problem in Maxent

On Oct 19, 11:48 pm, Navinder Singh <navinderjsi...@gmail.com> wrote:
> Mahmoud,
> Set your extent in spatial analyst to a raster u want to use as the base.
> Keeping this as extent u can then clip all others to this extent.
> This is done by-
> Spatial analyst>options>cell size (what you wish)>extent layer (specify here)> set mask
> open raster calculator
> E.g elevation=elevation (this will Now be clipped to your new extent)
> Do the same for all other layers.
> Hope this helps,
> Cheers,
> Navinder
>
> Sent from my iPad
>

> On 19 Oct 2010, at 10:23, Mahmoud Saleh Abdel-Dayem <msabdelda...@gmail.com> wrote:
>
>
>
> > Hi
> > I am trying to predict the distribution of sand fly species using 19
> > bioclim layers and elevation and slope in Maxent; but I couldn't add
> > the vegetation or land cover to the model, each time Maxent's message
> > tell me that that land cover or soil layers are with different cell
> > size, number of columns and rows. So, Please any one has an idea or
> > way to make soil and land cover layers with the sam cell size, number
> > of rows and columns like 19 bioclim layers.
>
> > Cheer
> > Mahmoud
>
> > --
> > You received this message because you are subscribed to the Google Groups "Maxent" group.
> > To post to this group, send email to max...@googlegroups.com.
> > To unsubscribe from this group, send email to maxent+un...@googlegroups.com.

[Saeed Hosseinian]

Dear Friends

I am trying to add slope and NDVI layers to the MaxEnt and run the model, but I cannot find how I do this. also how I can regulate the degree of layers for MaxEnt. Are they manage with GIS (Arc map)? 

Bests

SAEED

======================================================================

[Ulrik Pedersen]

This tutorial has the answers: http://ibis.colostate.edu/WebContent/WS/ColoradoView/TutorialsDownloads/A_Maxent_Model_v7.pdf

 

It will help you a lot to have a file to use as a mask that defines your modelling domaine and resolution. I made an R-code:

 

### To make an area of one pixel

library(raster)
xy <- matrix(rnorm(10000),100,100)
image(xy)
rast=raster(xy)
extent(rast) <- c(24,34,-24,-14)
projection(rast) <- CRS("+proj=longlat +datum=WGS84")
plot(rast)
xy <- matrix(rnorm(10000),1,1)
image(xy)
xy <- matrix(rnorm(10000),1,1)
xy <- matrix(rnorm(10000),1,1)
image(xy)
rast=raster(xy)
extent(rast) <- c(24,34,-24,-14)
projection(rast) <- CRS("+proj=longlat +datum=WGS84")
plot(rast)
writeRaster(rast,"C:/hej.asc",format="asci

 

 

The line "xy <- matrix(rnorm(10000),100,100)" defines a resolution of 100 x 100 cells in the modelling domain of 10 by 10 degrees and thereby a resolution of .10 degrees approximately 10 km.

The line "extent(rast) <- c(24,34,-24,-14)" defines where in the world the mask is placed. Adjust also in the line "extent(rast) <- c(24,34,-24,-14)".

 

Also I found that it helps to work with a Float-format in ArcMap (both the mask file and climate variables) and as a last step before creating the .asc file to multiply with 1 using the Rasta Calculator.

2014-01-11 Saeed Hosseinian <mesalina....@gmail.com>

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[Amir Sohail Choudhury]

Hello

For this, you have to make all maps similar with respect to coordinates, cell size. For this, you can use ArcGis.

In which, you have to extract your map using extract by mask then before saving go to Environment option

Then go to change Coordinate, Processing, Raster analysis according to your first map.

This will convert other maps and make it as like your first one. I mean cell size, coordinate system.