Due to SPAM attacks, new members must be approved before posting.  Please email when registering and your account will be approved.

Main Menu

Wetland Elevation Ranges

Started by rloiselle, May 10, 2010, 02:10:39 PM

Previous topic - Next topic


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!


Jonathan S. Clough

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