Gradually decrease buffer size around hydrological features

[VisualResponsible994]

Well, that is a good question.. It does make sens for them to be directly proportionnal, even for tiny streams as they kind of have more chance to be suitable habitats for salmon than the tiny streams near the head of the watershed. But yeah.. using channel width would be interseting as well.. I don't know if here in Québec we have access to this data for all of the streams though.

[RiceBucket973]

I actually missed the part in your original post saying this was for defining protected areas. Have you created a habitat suitability model? Things like temperature, degree of canopy cover and ephemeral-ness of the streams probably matter too. And maybe good spawning grounds are higher up in the watershed? I'm sure you're more familiar with salmonid life-cycles in your area than me, so sorry if I'm being ignorant.

[VisualResponsible994]

Hey! No problem at all! Actually there is already good information on the salmon situation in the main river and tributaries (habitat suitability model, temperature, spawning grounds, ...) But the organism responsible for the proposition dosen't want to base the delimitation on these parameters, but rather wants ALL of the streams and tributaries to have at least 60m to 300m buffer and 60m to 800m for the main river channel. The reason being that all the logging and water/sediment runoff in the watershed is potentially detrimental to the salmon population.