Required extent of data around study area?

[moorer98]

Hello,

I am a student working on my first SLAMM, so I hope this is not a dumb question.  I have compiled most of my data sets but I was wondering to what extent does one need to model out to?  I realize that the area needs to be rectangular, but can my input data be the smallest rectangle that the study area falls into or do you need to model all the way to the ocean?  I have data to the ocean, but in processing it in ArcGIS I am realizing that the area is "big" in that I am using LIDAR data and currently using a 1 meter pixel size.  This brings me to my next question, does it make sense to export the ASCII files at 1 meter or should I increase the pixel size?

Thank you,

Rich

[Amy Polaczyk]

Hello Rich,

This is a really good question. In principal, you do not need to model all the way out to the ocean. However, some points to consider:
A) including the ocean will provide important context for your study area. We include the ocean in the gross majority of our simulations.
B) in order to incorporate the effects of erosion it is necessary to include the ocean/land interface (at least 1-cell width of open ocean is needed since erosion is calculated for areas where 9 km of wave set-up is possible, the model will consider the area beyond the 1-cell of open ocean as it had infinite width)

1 meter is a very small pixel size and it may only make sense to output at this resolution if the resolution of the input data the same or higher (1 meter or smaller) and the project is within the memory capabilities of the model (< 4 GB since the model is 32-bit).

Hope this info helps. Please let us know if you have other questions.

Cheers,
Amy