Objectives and Methods
Project Aims:
- Exact modelling of the effects of forest edges and in-homogeneities on the turbulent flow
- New assessment of methodes to measure fluxes of trace
gases
- Quantification of uncertainties of measurement over comlex
terrain
Objectives of the sub-projects:
Boundary Layer Modelling (IHM)
- Scheme of the coupled Soil-Vegetations-Boundary Layer Model HIRVAC
- Development of a instationare 2-D-Version of HIRVAC under consideration of highly resolved vegetation structure and the transition between forest-clearing-forest
- Parametrisation of drag coefficients and advection of momentum in HIRVAC-2D regarding the results of the LES-Simulation
Large-Eddy-Simulation (ISM)
- LES of the flow and the passive trace gas fluxes at forest
edges and comparison with field and wind tunnel
measurements
- Vegetation and sub grid models for ∆x~ trunk
diameter
Field measurements (IHM)
- Recording of the turbulent flow and analysing of the
fluxes (momentum, energy, and mass) along a transect through a
heterogeneous forest stand with high spatial (horizontal ca.
50 m, vertical 10 m) and temporal (20 Hz)
resolution
- Derivation of model parameters (drag coefficients, mixing
length) from vegetation structure and turbulence
measurements
- Setup of a data basis as reference
Wind Tunnel (ILR)
- Data basis für Randbedingungen und zur Verifizierung numerischer Modelle
- Untersuchung verschiedener Baumformen und jahreszeitlicher Vegetationsstufen unter Laborbedingungen
Vegetation Assessment (IPF)
- Terrestrial laser scanning of the forest stand and derivation of canopy elements (Digital Terrain Modell, tree height, tree diameter, tree position, mean tree distance)
- Development of voxel structures from 3D-point clouds und providing of voxel spaces with several attributes for the derivation of the vegetation density
- Measurement and analysis of tree swaying