Hello all!
I'm trying to conduct an SDM analysis in R regarding a species which only occurs in the intertidal area.
I need to be able to restrict my geographical range to a range of points in the coastline around the continents and islands, in order to prevent the software from predicting species occurrences, lets say, for the countryside (places with similar environmental characteristics but very very far away from the coast).
I am aware I can do it with a shapefile but have yet to find one (and the way to implement it) that fits.
Can anyone offer me a nudge in the right direction please?
Jin Li I am not sure I can just crop the area given that I want to predict in a strip of land accross all continents (basically the whole coastline). But I will try that function for sure.
I'll also look into the e-mail address you provided.
Thank you so much!
I am not sure if this might work, or classification has been used worldwide. The US Fish and Service has used the Classification of Wetlands and Deep Water Habitats developed by Cowardin et al about 1972 I think. The US has been fully Classified in GIS, but I am not sure if it has been expanded world wide. The data base of this is classified polygons including intertidal areas. As with any remote land use classification, some degree of ground truthing is also typically used. I don't have a USFWL contact to share for this. Once a land use or condition is classified into polygons, it would be easy in GIS to select desired intertidal polygon elements by specialists.
https://www.fws.gov/wetlands/documents/classification-of-wetlands-and-deepwater-habitats-of-the-united-states.pdf
This id the Cowardin reference, published in 1977.
Hi,
This might not be what you need, but it will help you in the future. When you need a shapefile that doesnt exist but you have an idea what you are looking for. You can just draw it yourself and save it as a shapefile. You dont need any GIS software or any expertise in the subject.
Just follow this link
https://geojson.io/#map=2/20.0/0.0
use the poligon tool to create the raster you need and save it as a shapefile.
I found this a good source. Hope it can help
https://cfss.uchicago.edu/notes/raster-maps-with-ggmap/
Hello Francisco, you can download a global dataset showing intertidal areas here: https://www.intertidal.app/download
Tobias Fremout Looks good! Do you think I can use this data to crop out the world map?
Francisco O. Borges yes they are raster files, you could mask the non-tidal zones with the mask function in the R raster package
Tobias Fremout I'm having dificulty importing this into R, since I get multiple tif files from specific areas of the globe (instead of a single tif file for the whole globe). Am I missing something in the website? Or do I need to find a way to knit them together?
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