SLAMM Forum

General Category => Model Formulation & Parameters => Topic started by: Elena V on September 04, 2013, 06:10:41 PM

Title: Freshwater influence accretion rates
Post by: Elena V on September 04, 2013, 06:10:41 PM
I recently noticed that accretion is not occurring as expected in areas defined as "freshwater influenced."

I first ran my model with an inverse linear relationship between accretion and elevation (low = 2 mm/year, high = 6 mm/year) in a region that was "freshwater influenced". All categories without the empirical relationship were assigned accretion of 3 mm/year.

Then I ran the same model, but with 2x the accretion rates and found no difference between the model outputs within the region of freshwater influence. There were differences outside the freshwater region.

To confirm, I ran the low/high accretion scenarios without freshwater influence and saw a major difference.

Am I implementing the freshwater influence module incorrectly? Or is it just a bug since this option is still relatively new in SLAMM?
Thanks!
Title: Re: Freshwater influence accretion rates
Post by: Jonathan S. Clough on September 05, 2013, 06:59:31 AM
This is an interesting observation.  We had not yet experienced this problem.  We'll look into the code and test this out and get back to you shortly.  -- J
Title: Re: Freshwater influence accretion rates
Post by: marco.propato on September 12, 2013, 11:14:47 AM
Hi Elena,
I could not reproduce your problem. One possible explanation of your results is that the turbidity factor in the fresh flow parameters is used and set to zero (or a very small number). In fact, as it is described in the users manual, if the turbidity factor is used, then the actual accretion rates in the fresh flow areas are given by the nominal values multiplied by the specified turbidity factor.

If that is not the case then I would be happy to have a look at your project and see if I can identify the cause.

Marco