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| Titel |
Free Energy as Link to Hydrological Responses and Landscape Organization |
| VerfasserIn |
Conrad Jackisch, Erwin Zehe, Uwe Ehret, Thomas Graeff, Theresa Blume |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250042739
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| Zusammenfassung |
| The water balance equation remained the single most basis of all hydrological models
during the last decades. While we strive to find ways to integrate the whole
human-hydro-geo-eco-system into the water balance, energy as driver for the processes we
hope to capture is often forgotten. In order to advance hydrological models catchments as
self-organizing systems are topic in many publications since several years (e.g. Grayson and
Blöschl 2001). Recent studies propose the concept of optimality for hydro-eco-systems
(Schymanski and Kleidon 2008). Moreover the arrangement and persistence of
macropores, as highly dissipative structures and as one common bio-geo interaction,
were shown to result in faster dissipation of Helmholtz Free Energy (Zehe et al.
2009).
The hypothesis that landscapes might arrange in a way to maximize the dissipation of free
energy has been the starting point of this analysis. Based on data from three completely
different catchments in Chile and Germany we conducted a model assessment of the
behavior of the Helmholtz Free Energy of the soil water domain and the entropy and
heat exchange at the atmospheric boundary for different landscape organizations
at representative hillslope settings using the model CATFLOW. In a second step
we sought further for internal topologies and functional entities by developing a
toy-model.
The study revealed quickly that the different components of the energy balance of the
hydro-eco-system cross several orders of magnitude. Hence a mere first-order approach to
maximized dissipation of Free Energy is not giving us any enhanced insight nor does it
reflect reality. We propose a conditioned schemes as e.g. when it rains the option to
dissipate energy through evaporation or transpiration is basically closed and vise versa.
Further we discuss approaches to understand the hydro-geo-eco-system beyond
mechanized descriptions of highly conceptualized compartments through functional units. |
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