I am modeling an area that includes the zone of tidal influence for a river feeding into a bay. Does the model have any kind of damping effect on sea level rise as you move upstream, or does it simply assume that the same sea level rise is experienced for all water with SLAMM category 17?
You can use "input subsites" to specify a diminishing tidal range as you move up river. However, the projected tide range is predicted to remain constant throughout a model simulation. (SLAMM is not a hydrodynamic model.)
Additionally, the same vertical sea level rise is experienced for all "Estuarine Open Water" when the salinity model is not utilized. The assumption is that for all tidally influenced areas, the change in mean tide level will be the same regardless of location within the estuary.
A few additional points:
- When the (relatively simple) salinity model is utilized, yearly freshwater flow is a site parameter and this affects predicted water elevations up-estuary. In this case, the salt wedge is assumed to move vertically in a uniform manner along with oceanic sea level rise. The salinity model takes considerably more time and model calibration to implement, however.
- Tidal fresh marshes and tidal swamp elevations are nearly always located below the "salt elevation" and usually below MHHW. Their elevation ranges should be set accordingly in the elevation analysis entry screen. See page 16 of the Technical Documentation for more info.