How to obtain .asc files

[DAOUDI mohamed]

Hi,

A newbie here, so sorry if the question has been asked before.

I am stack at the phase of specifying the layers file (the .Asc file). My question is where to find raw data for the Moroccan area and how to convert them to an .asc file for use in the Maxent software.

Thank you.

[mjb...@york.ac.uk]

Hello - I am not sure what data you are after (climate variables, vegetation etc), but a good hunt around on the internet will produce many of them. search for Bioclim as a starting point.

Once downloaded, you need to crop and tidy your rasters (put simply, maps containing data) to your area of interest and then convert to the asc format. Conventionally, many people use GIS programs such as ARCGIS or GRASS or alternatively R is now increasingly used for spatial mapping. All of which can convert your rasters to asc.

The above is a very simplistic way of putting things (I have missed out many steps) and I would strongly advise in finding a good beginners guide to spatial mapping such as Brunsdon and Comber, 2015. 'R for spatial analysis & mapping'.

best wishes

Michael

[DAOUDI mohamed]

Mainy thanks Michael,

Mohamed 

[Jamie M. Kass]

There are a number of good global datasets for climate variables: Worldclim, CHELSA, ecoclimate, etc. Google will turn them up for you. Most of these datasets offer bioclimatic variables, which are variants of temperature and precipitation that are linked to biological processes. Some of these variables are not in ascii form, but you can convert them if you’d like using ArcGIS, QGIS, or R. Or you can run Maxent through R and not have to worry about file format.

Jamie Kass
PhD Candidate
City College of NY

[DAOUDI mohamed]

Thank you so much for your answer and your time