Ecological Effects of Water-level Fluctuations in Lakes
Ecological Effects of Water-level Fluctuations in Lakes

Author: Karl M. Wantzen

Publisher: Springer Science & Business Media

Published: 2009-05-06

Total Pages: 184

ISBN-13: 1402091923

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Most aquatic ecosystems have variable water levels. These water-level fluctuations (WLF) have multiple effects on the organisms above and below the waterline. Natural WLF patterns in lakes guarantee both productivity and biodiversity, while untimely floods and droughts may have negative effects. Human impacts on WLF have led to a stabilization of the water levels of many lakes by hydraulic regulation, untimely drawdown due to water use, or floods due to water release from hydropower plants in the catchments. This book provides a first review in this field. It presents selected papers on the ecological effects of WLF in lakes, resulting from a workshop at the University of Konstanz in winter 2005. Issues addressed here include the extent of WLF, and analyses of their effects on different groups of biota from microorganisms to vertebrates. Applied issues include recommendations for the hydrological management of regulated lakes to reduce negative impacts, and a conceptual framework is delivered by an extension of the floodpulse concept for lakes. Current impacts on water use, including increasing demands on drinking and irrigation water, hydropower etc., and climate change effects on WLF make this book an essential resource for aquatic ecologists, engineers, and decision-makers dealing with the management of lake ecosystems and their catchments.

Physics of Lakes
Physics of Lakes

Author: Kolumban Hutter

Publisher: Springer Science & Business Media

Published: 2011-07-29

Total Pages: 709

ISBN-13: 3642191126

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The overwhelming focus of this 2nd volume of “Physics of Lakes” is adequately expressed by its subtitle “Lakes as Oscillators”. It deals with barotropic and baroclinic waves in homogeneous and stratified lakes on the rotating Earth and comprises 12 chapters, starting with rotating shallow-water waves, demonstrating their classification into gravity and Rossby waves for homogeneous and stratified water bodies. This leads to gravity waves in bounded domains of constant depth, Kelvin, Poincaré and Sverdrup waves, reflection of such waves in gulfs and rectangles and their description in sealed basins as barotropic ‘inertial waves proper’. The particular application to gravity waves in circular and elliptical basins of constant depth leads to the description of Kelvin-type and Poincaré-type waves and their balanced description in basins of arbitrary geometry on the rotating Earth. Consideration of two-, three- and n-layer fluids with sharp interfaces give rise to the description of gravity waves of higher order baroclinicity with experimental corroboration in a laboratory flume and e.g. in Lake of Lugano, Lake Banyoles and Lake Biwa. Barotropic wave modes in Lake Onega with complex geometry show that data and computational output require careful interpretation. Moreover, a summer field campaign in Lake of Lugano and its two-layer modal analysis show that careful statistical analyses of the data are requested to match data with computational results. Three chapters are devoted to topographic Rossby waves. Conditions are outlined for which these waves are negligibly affected by baroclinicity. Three classes of these large period modes are identified: channel modes, so-called Ball modes and bay modes, often with periods which lie very close together. The last chapter deals with an entire class of Chrystal-type equations for barotropic waves in elongated basins which incorporate the effects of the rotation of the Earth.

Physics of Lakes
Physics of Lakes

Author: Kolumban Hutter

Publisher: Springer Science & Business Media

Published: 2010-11-10

Total Pages: 475

ISBN-13: 3642151787

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This first volume in the treatise on the Physics of Lakes deals with the formulation of the mathematical and physical background. A large number of lakes on Earth are described, presenting their morphology as well as the causes of their response to the driving environment. Because the physics of lakes cannot be described without the language used in mathematics, these subjects are introduced first by using the simplest approach and with utmost care, assuming only a limited college knowledge of classical Newtonian physics, and continues with increasing complexity and elegance, starting with the fundamental equations of Lake Hydrodynamics in the form of ‘primitive equations’ and leading to a detailed treatment of angular momentum and vorticity. Following the presentation of these fundamentals turbulence modeling is introduced with Reynolds, Favre and other non-ergodic filters. The derivation of averaged field equations is presented with different closure schemes, including the k-ε model for a Boussinesq fluid and early anisotropic closure schemes. This is followed by expositions of surface gravity waves without rotation and an analysis of the role played by the distribution of mass within water bodies on the Earth, leading to a study of internal waves. The vertical structure of wind-induced currents in homogeneous and stratified waters and the Ekman theory and some of its extensions close this first volume of Physics of Lakes. The last chapter collects formulas for the phenomenological coefficients of water.

Nonlinear Internal Waves in Lakes
Nonlinear Internal Waves in Lakes

Author: Kolumban Hutter

Publisher: Springer Science & Business Media

Published: 2011-11-25

Total Pages: 292

ISBN-13: 3642234380

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Internal wave dynamics in lakes (and oceans) is an important physical component of geophysical fluid mechanics of ‘quiescent’ water bodies of the Globe. The formation of internal waves requires seasonal stratification of the water bodies and generation by (primarily) wind forces. Because they propagate in basins of variable depth, a generated wave field often experiences transformation from large basin-wide scales to smaller scales. As long as this fission is hydrodynamically stable, nothing dramatic will happen. However, if vertical density gradients and shearing of the horizontal currents in the metalimnion combine to a Richardson number sufficiently small (

Physics of Lakes
Physics of Lakes

Author: Kolumban Hutter

Publisher: Springer

Published: 2010-11-11

Total Pages: 0

ISBN-13: 9783642151774

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This first volume in the treatise on the Physics of Lakes deals with the formulation of the mathematical and physical background. A large number of lakes on Earth are described, presenting their morphology as well as the causes of their response to the driving environment. Because the physics of lakes cannot be described without the language used in mathematics, these subjects are introduced first by using the simplest approach and with utmost care, assuming only a limited college knowledge of classical Newtonian physics, and continues with increasing complexity and elegance, starting with the fundamental equations of Lake Hydrodynamics in the form of ‘primitive equations’ and leading to a detailed treatment of angular momentum and vorticity. Following the presentation of these fundamentals turbulence modeling is introduced with Reynolds, Favre and other non-ergodic filters. The derivation of averaged field equations is presented with different closure schemes, including the k-ε model for a Boussinesq fluid and early anisotropic closure schemes. This is followed by expositions of surface gravity waves without rotation and an analysis of the role played by the distribution of mass within water bodies on the Earth, leading to a study of internal waves. The vertical structure of wind-induced currents in homogeneous and stratified waters and the Ekman theory and some of its extensions close this first volume of Physics of Lakes. The last chapter collects formulas for the phenomenological coefficients of water.