This forum is shutting down! Please post new discussions at

coastal vulnerability model - exposure ranks for different coastal geomorphology

Can anyone help provide some feedback on some exposure ranks?  My team is trying to run the coastal vulnerability model for the Liberian coastline (entire country).

For the exposure ranks we've come up with the
following (based on the guidelines:

- beach (mangrove behind): 4 (still beach but
slightly less exposure due to mangroves behind)

- beach (human settlement behind): 5 (highest possible
exposure due to settlement behind)

- mangrove: 1 (lowest possible exposure)

- mud: 5 (highest possible exposure)

- rock (harbor break): 1 (lowest possible exposure)

- rocky: 3 (more exposed than mud but less exposed
than beach)

- sand/mangroves: 3 (average between sand and

- sandy bank: 5 (highest possible exposure)

- settlement: 3 (just a guess, took the middle

Thank you!


  • Hi, 

    You are combining two different types of model inputs in your list above.  The geomorphology type is a classification that refers to the type of shoreline.  For example, sandy bank, sand, mud, rock all refer to the shoreline type, or geomorphology. Settlement, in and of itself isn't a description of the shoreline.  It might be built on a sandy beach, or have a seawall.  Sometimes you have to look at satellite imagery to see what the shoreline looks like in a region if it's classified with a descriptor that isn't very informative.  You don't need to worry about the concept of 'exposure' when classifying geomorphology, the model accounts for that elsewhere.  It's strictly about the shoreline type, and how prone it is to erosion.

    The presence of habitats are accounted for elsewhere in the model as well.  You will want to have a shapefile of your mangrove habitat, and it will get a corresponding habitat rank.  Usually, the places that I work where there's mangrove there's 'mud' as the shoreline type, and occasionally rock substrate fronting the mangrove field.

    Does this make sense?  Happy to provide commentary on the ranks once you've pulled out the habitat and clarified the 'settlement' shoreline.  Also, for a little help assigning ranks to specific shoreline categorizations take a look at the shoreline types here, and cross-reference that against Table 4.1 in the UGuide.


  • Thanks Jess! Yes makes sense. I'll share this with my team and get back to you if we have further questions.  Would you be willing to look at some outputs with us and help us make sure we're interpreting them correctly, including understanding how the various default values might influence the model outputs?  Happy to take this conversation to e-mail if easier.
  • Yes, I would be more than happy to look at outputs, etc.  I think it's preferable to keep questions like yours above about model parameters etc. on the forum so others can benefit from them.  But as far as outputs go and more in depth questions about your application you are more than welcome to email me at

  • Thank you, we'll keep more general questions here and specific questions about our outputs via email.
Sign In or Register to comment.