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Aquatic Ecosystems and the Second Law Inequality: Estimating Alpine Fish Habitats Using Entropy Generation Minimization

Author(s): Jeff A. Tuhtan; Silke Wieprecht

Linked Author(s): Silke Wieprecht, Jeffrey Tuhtan

Keywords: No Keywords

Abstract: Conventional aquatic habitat models require statistical analysis of field data or expert knowledge of abiotic-biotic relations to assess habitat suitability. More recently, individual-based models have also emerged using bioenergetic principles to estimate organism locomotion and behavior. The study of fish energetics and locomotion is often segregated, where energetics is quantitatively considered via‘first law’conservation approaches. Due to the complexity of the local flow field, works on fluid-body interactions during locomotion are to a large extent restricted to phenomenological investigation. This work broadens the conceptual framework by applying entropy generation minimization (EGM), allowing for the simultaneous consideration of energy quality and quantity. Combining hydromechanics, thermodynamics and heat transfer, EGM provides the missing link between swimming performance, metabolism, and the flow field, forming an expanded‘second law’perspective. Here we present a new type of aquatic ecosystem model fusing abiotic-biotic metrics using principles from the thermodynamics of irreversible, finite-time, finite-sized systems. Building upon recent advances in theoretical and phenomenological studies of fish energetics and locomotion, a model including flow pattern and wate temperature is derived to assess alpine fish habitats. The model is comprehensively compared to the exper knowledge based fuzzy logic model CASi Mi R-Fish on sample of 30 alpine river reaches. Results from this new model concept under steady conditions are found similar to CASi Mi R. Differences between the two models become pronounced when the models are considered under unsteady conditions.


Year: 2012

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