Modeling phytoplankton community in reservoirs. A comparison

DI MAGGIO, J.; FERNÁNDEZ, C.; PARODI, E.R.; DIAZ, S.; ESTRADA, V.

JOURNAL OF ENVIRONMENTAL MANAGEMENT

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 p. 31 - 52

0301-4797

In thispaper we address the formulation of two mechanistic water quality models thatdiffer in the way the phytoplankton community is described. We carry outparameter estimation subject to differential algebraic constraints andvalidation for each model and comparison between models performance. The firstapproach aggregates phytoplankton species based on their phylogeneticcharacteristics (Taxonomic group model) and the second one, on theirmorpho-functional properties following Reynolds´ classification (Functionalgroup model). The latter approach takes into account tolerance and sensitivity toenvironmental conditions. The constrained parameter estimation problems areformulated within an equation oriented framework, with a maximum likelihoodobjective function. The study site is Paso de las Piedras Reservoir(Argentina), which supplies water for consumption for 450,000 population.Numerical results show that phytoplankton morpho-functional groups more closelyrepresent each species growth requirements within the group. Each modelperformance is quantitatively assessed by three diagnostic measures. Parameterestimation results for seasonal dynamics of the phytoplankton community andmain biogeochemical variables for a one-year time horizon are presented andcompared for both models, showing the functional group model enhancedperformance. Finally, we explore increasing nutrient loading scenarios andpredict their effect on phytoplankton dynamics throughout a one-year timehorizon.