# LULC in coastal vunerability model

Dear Community,

I am assessing the impact of land use changes on some ES. I have LULC maps for present and future (optimistic and pessimistic) scenarios, reflecting different levels of environmental law compliance.

Regarding the coastal vulnerability model, I am uncertain if only the vegetation from the pixels directly touching the ocean influences the model outputs, or if pixels at a greater distance from the coast also affect the model.

I aim to calculate the gains and losses of vegetation along the coastline in different scenarios to understand the impact of land use changes on coastal vulnerability.

I am running the model with a 30 m resolution. If I create a 30 m buffer along the coastline to extract the LULC, would be enough? Or should I use a wider buffer?

Thank you!

Hi @fmr -

You can include vegetation at greater distances from the coastline, both into the ocean, and inland. For each vegetation type, you’ll specify a distance over which it provides protection. So the model will look in a radius of that distance around the vegetation type to see if/where it intersects the shoreline, and if so it will provide some sort of protection to the places it intersects.

We often include habitats such as coastal wetlands and coastal forests, which can extend a bit inland. I wouldn’t go too far inland though, since the model is really focused on the effects to the shoreline itself, and forest that’s 10km inland isn’t going to protect a community located right on the coast.

I’ve used inland vegetation within about 1km of the coast for a few projects, but it would be worth looking at other studies that have used this model to see what distances they’ve used for including land-based habitat types. You can check out both NatCap studies and wider InVEST community studies from the Publications page of our website.

On the topic of resolution, 30m sounds rather small to me. What is your total area of interest? If it’s large, the model will take a very long time to run at 30m. And given the simplicity of the model, it’s best not to use it at too fine a resolution, let we give the impression that it is providing more specific detail about a particular place than it really is. The smallest resolution I’ve seen it used in our work is more like 100m. It can work at 30m, and it’s fine to run it at that scale, just be aware of its limitations when you’re reporting results and making decisions.

~ Stacie