General Category => Using SLAMM => Topic started by: rloiselle on May 10, 2010, 02:10:39 PM

Title: Wetland Elevation Ranges
Post by: rloiselle on May 10, 2010, 02:10:39 PM
Does anybody understand the differences between the Tables on pg. 10 of the Technical Manual and Pg.14 of the Users Manual.  They seem to contradict each other when I plug in my values to the framework.

Ex.  Technical Manual (pg.10): Reg.Flooded Marsh, min.Elev = MTL and max.Elev = Ave(MHHW, SB), My data = 0 and 1.385
Users Guide (Elevation Analysis, Pg 14): Reg.Flood.Marsh, min.Elev = 0 Meters (MTL) and max Elev. = 1.2 HTU, my data = 0 and 1.3992

Is this because the Technical Manual is referring to a different rule set for the wetlands presented in table 2 (pg 10) when there is water present at the upper end of the wetland?

Thanks for clarification!

Title: Re: Wetland Elevation Ranges
Post by: Jonathan S. Clough on May 17, 2010, 07:47:13 AM
Thanks for this inciteful question:

The original (SLAMM5) conceptual-model formulation was the half-way point between MHHW and MTL based on evaluation of various LiDAR data sets.  This was "hard-wired" into the model code.

Within SLAMM6 the conceptual model for elevation ranges is flexible.  However, the "half-way-point" between two elevations is not one of the input options.  The conceptual model must be specified in meters, or as a function of the tide range (GT or Salt Bound).  For this reason, we set the boundary to 1.2 HTU (or 120% of MHHW) which is, as your analysis shows, usually essentially the same as the half-way point between MHHW and the "salt boundary." 

However, I missed making this update to the Technical Documentation on Page 10.  I have fixed that now and it will be part of the next draft release later this month.  Sorry about the confusion.

-- Jonathan