Simulating Population Dynamics in an Ecosystem Context Using Coupled Eulerian-Lagrangian Hybrid Models (CEL HYBRID Models)

摘要

CEL HYBRID models are a new method for coupling Eulerian and Lagrangian reference frames so that the higher trophic levels of an aquatic ecosystem, such as fish and shellfish, can be systematically and realistically simulated. In the Eulenan-Lagrangian coupling, the influence of aquatic organisms on water quality is evaluated by spatially averaging relevant characteristics of the organisms within a cell, such as biomass, while the population dynamics of individual species are modeled by treating organisms as individuals or groups of individuals. Water quality is often analyzed using spatially averaged cells, where each cell represents one uniform environment, with no variation in attributes within the cell. On the other hand, the population dynamics of species are often analyzed by tracking individuals, or groups of individuals, all of which are considered to reside within one spatially averaged environment. Spatially averaging characteristics, such as mass, of a group of organisms' participation in the chemical processes of the aquatic environment, such as dissolved oxygen uptake and excretion, to be evaluated. However, species population dynamics, which determine the number of organisms in each cell, are usually modeled with a Lagrangian reference frame. CEL HYBRID models allow for the analysis of higher trophic level processes with minimal distortion and loss of information by coupling the two frames of reference and, thereby, exploiting the advantages and minimizing the disadvantages associated with each.