I’m trying to modify the habitat rank results from the coastal vulnerability model (my goal is to recalculate the habitat rank for each shoreline segment without each of the individual habitat types, to see where each habitat type has the strongest effect on the coastal exposure index), but am having trouble recreating the current habitat rank from the model outputs.
I created a csv file with one record for each shoreline segment, containing the final habitat rank (from 1_d_natural_habitats.csv) and the presence/absence of each habitat type (using the extract values to points tool in ArcGIS to extract the values from the 1_d_HAB_XX_[habitat]_influence_on_shore.tif files).
Next, I wrote an R script that calculates the habitat rank for each shoreline segment from the individual habitat ranks, using the equation from the model user’s guide. When I calculate the habitat rank in the same way that (I think) the model does, I don’t get the same results. For example, one shoreline segment is ‘within range’ of three habitat types, with ranks of 1, 4, and 2. I calculate that the final habitat rank should be 2.226092, but the habitat rank output from the model is 1.40884.
I’ve double-checked the individual habitat ranks that I’m using (they match what was used in the model run). I also tried calculating the habitat rank with ‘missing’ habitats (those out of range of the shoreline segment) set to 5 rather than just excluding them from the calculation, but still didn’t get the habitat ranks calculated within the model. In addition, neither my calculated habitat rank nor the model output rank matches the ranks in Appendix B of the User’s Guide (my calculated rank is close, but not exact), even though my protection distance and rank for habitats matches those suggested in the user’s guide.
I’m using version 3.6 of the coastal vulnerability model. Any help understanding why my calculated habitat ranks differ from the model outputs would be great! I can share relevant outputs and the R script if that’s helpful. Thanks!