A zero-dimensional model for phytoplanktonicproduction in turbid, macro-tidal, well-mixed estuaries is proposed. It is based on the description of light-dependentalgal growth, phytoplankton respiration and mortality. The model is forced by simple time-functions for solar irradiance, water depth and light penetration. The extinction coefficientis directly related to the dynamics of suspended particulate matter. Model results show that the description of phyto-plankton growth must operate at a time resolution sufficientlyhigh to describe the interference between solarly and tidallydriven physical forcing functions. They also demonstrate that in shallow to moderately deep systems, simulations using averaged, instead of time-varying, forcing functions lead to significant errors in the estimation of phytoplankton productivity. The highest errors are observed when the temporalpattern of light penetration, linked to the tidal cycle of solidssettling and resuspension, is neglected. The model has alsobeen applied using realistic forcing functions typical of two locations in the Scheldt estuary. Model results are consistentwith the typical phytoplankton decay observed along the lon-gitudinal, seaward axis in the tidal river and oligohaline part of this estuary.
Located in
Library
/
No RBINS Staff publications
