Description: Das Projekt "Dynamik der Tiefenwassermischung im Genfer See" wird vom Umweltbundesamt gefördert und von Ecole Polytechnique Federale de Lausanne, Institut d'Hydraulique et d'Energie durchgeführt. Deep water mixing in the Leman has important consequences for the development of the trophic state of a lake. A multi-annual heating trend of the Leman has been observed which leads to progressive oxygen depletion in the deep layers coupled to an increasing phosphorous release from the bottom sediment. Since 1986, the LRH-EPFL has regularly (about each month) taken high precision profiles of water density parameters at several stations in the Leman. This data base together with high quality atmospheric boundary layer data from Cointrin airport will serve to investigate two deep water mixing mechanisms for the Leman: vertical mixing and inter-basin density currents. The origin, the seasonal dynamics and spatial variability of these mechanisms will be addressed. This data base will be supplemented by taking data of the same type for specific situations and in addition, a set of micro-scale water density profiles. The latter will make it possible to express deep water mixing in terms of mixing coefficients which is not possible on the basis of the present data. Subsequently the concepts derived from this data analysis will be applied to adapt a numerical model of seasonal heat flux dynamics (DYRESM) to the Leman. The results of the project will help to improve the understanding of the deep-water dynamics in the Leman. They will be directly applicable to ecological modelling where deep water processes are presently ill-defined. They will help in management planning aspects to counteract deep water oxygen depletion through measures such as artificial aeration.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Populationsdynamik ? Eutrophierung ? Phosphorbelastung ? Seen ? Genfer See ? Lausanne ? Flugplatz ? Phosphor ? Pflanzensamen ? Sauerstoff ? Hypolimnion ? Tiefenwasser ? Tiefenwasserbelüftung ? Daten ? Energie ? Management ? Oberflächengewässer ? Seenschichtung ? Gewässerschutz ? Sediment ? Wasser ? Modellierung ? Planetarische Grenzschicht ? Belüftung ? Datenbank ? Heizung ? Kenngröße ? Sauerstoffmangel ? See [Binnengewässer] ? Seenerwaermung ? Wassermischung ? Ökomodell ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1992-10-01 - 1995-09-30
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