Kopplung eines Vegetationsmodells mit abiotischen Standortbedingungen. Übertragung der Rückkopplungen zwischen den Standortfaktoren und verschiedenen Parametern des Röhrichtwachstums durch Transferfunktionen. Vegetationsmodell: • Modellierung des Wachstums und der Ausbreitung von Phragmites australis und Bolboschoenus maritimus • Prozesse: Wachstum, Mortalität und Ausbreitung durch Expansion der Rhizome • Zustandsvariablen: Rhizombiomasse, Wurzelbiomasse und oberirdische Biomasse Standortinformationen: • dynamisch in Raum und Zeit • als Raster in die Modellierung eingebunden Transferfunktionen: • Effekt der Vegetation auf Standortfaktor: Wert der Funktion ändert sich in Abhängigkeit von der Biomasse • Antwort der Vegetation auf die Standortbedingungen: Wert der Funktion ändert sich in Abhängigkeit vom Standortfaktor
Das Projekt "Improved wind energy assessment based on coupled wind, terrain and vegetation modeling (WindLand)" wird vom Umweltbundesamt gefördert und von Ecole Polytechnique Federale de Lausanne (EPFL), Faculte ENAC, IIE, Laboratoire d'ingenierie eolienne et d'energie renouvelable durchgeführt. One of the main sources of uncertainty during the design and operation of wind energy projects is associated with our current limited ability to predict wind and turbulence at spatial and temporal scales relevant to wind turbine operation, particularly over complex terrain. Many mountainous regions with high wind energy potential (including the Jura region in Switzerland and the Carpathian Mountains in Romania) are characterized by multi-scale variability of land surface properties (topography and vegetation cover), which strongly affects the spatial distribution of wind and turbulence and, in turn, wind-turbine performance. Despite the recent efforts to develop high-resolution eddy-resolving flow simulation techniques such as Large-Eddy Simulation (LES) for assessing wind energy projects, their application to mountainous regions is still in its infancy. In order to be effective, LES needs to be properly coupled with high-resolution information of the relevant land surface properties, namely topography, aerodynamic surface roughness, and vegetation structure of tall canopies. This information could potentially be obtained using the latest advances in wavelet-based multi-resolution digital terrain modeling and vegetation modeling. The proposed research aims at developing and assessing a framework that integrates terrain and vegetation modeling concepts and tools in support of accurate wind modeling for wind energy applications over complex terrain. To achieve this, we propose a multidisciplinary approach that consists of coupling the following main modeling elements: (1) a new-generation tuning-free Large-Eddy Simulation technique for high-resolution predictions of wind and turbulence over complex terrain, with and without wind farms; (2) very high resolution Digital Elevation Models linked with novel, wavelet-based generalization and filtering techniques to provide description of the surface properties at the relevant scales; and (3) landscape and vegetation models to predict the potential feedbacks between atmospheric boundary layer processes (fluxes), as affected by the wind farms, and vegetation patterns. The resulting modeling framework will be applied to two case study areas for which high resolution terrain data will be available: one in the Swiss Jura region, and the other in the Romanian Carpathians. The proposed new modeling framework is expected to be a powerful tool for optimizing the design and operation of wind farms. In particular, it will be useful to maximize wind energy production and minimize fatigue loads (and associated maintenance costs) in wind farms. It will also allow us to study the effects of wind farms on land-atmosphere exchanges and fluxes of momentum, heat and water vapor, which are expected to affect the near-surface air temperature and moisture and, in general, the local meteorology. (...)
Das Projekt "Paleo-environmental and modeling insights into Mediterranean fire-vegetation interactions in response to Holocene climate and land use changes" wird vom Umweltbundesamt gefördert und von Universität Bern, Departement Biologie, Institut für Pflanzenwissenschaften durchgeführt.
Das Projekt "Modelling sequential biosphere systems under climate change for radioactive waste disposal" wird vom Umweltbundesamt gefördert und von Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH durchgeführt. Objective: The project will provide a scientific basis to assess the safety of radioactive waste repositories in deep formations, with regard to the possible long-term impacts. Two complementary strategies will provide representation of future climate changes using respectively analysis of extreme situations and a continuous simulation over the next 1,000,000 years. Climate and vegetation models of different spatio-temporal scales will therefore be used to simulate the time series of climate and vegetation in various European areas. These results will be used to derive the nature of the human environments (i.e. the biosphere systems) through which radionuclides, coming from the repository, may transfer to Man. Finally these exposure and migration pathways will be described for three selected biosphere systems using two different approaches: a discrete one commonly used and a more innovative transitional one. Achievements: Work Package 1: Consolidation of the needs of the participating European waste management agencies in order to harmonise requirements for performance assessment requirements; Work Package 2: Development of methodology to provide climate models for regional discrete climate states and associated vegetation for periods of 100,000 years or more; Work Package 3: Development of a methodology to provide climate models for continuous representation of regional climate states and associated vegetation for periods of up to 100,000 years; Work Package 4: To adapt the output from the climate models developed in Work Packages 2 and 3 to the representation of biosphere systems under different climates to the requirements of performance assessment models; Work Package 5: To disseminate the results of Work Packages 1 to 4 through a final seminar and project documentation. In the first seven months of the project, work is nearly completed on Work Package 1 (together with Deliverables 1 and 2), and work has been initiated on Work Packages 2, 3 and 4. Prime Contractor: National Radioactive Waste Management Agency of France, Scientific Division Biosphere and Environment Section; Chatenay Malabry; France.