GaussPlumeModelle

GaussPlumeModelle are mathematical representations used in atmospheric dispersion modelling to estimate the concentration field of pollutants emitted from a continuous point source under relatively steady meteorological conditions. They are widely used in environmental assessment, regulatory compliance, and industrial hygiene to predict downwind ground-level concentrations and to assess exposure and risk.

The core of a GaussPlumeModel is the Gaussian plume solution, which expresses the concentration C at a downwind distance x, crosswind distance y, and height z as a function of emission rate Q, mean wind speed u, and vertical and horizontal dispersion coefficients σ_y and σ_z. A common form is:

C(x,y,z) = Q / (2π u σ_y σ_z) × exp(-y^2/(2σ_y^2)) × [exp(-(z - H)^2/(2σ_z^2)) + exp(-(z + H)^2/(2σ_z^2))].

Here H is the effective stack height, and the terms account for ground reflection. The dispersion coefficients σ_y and σ_z depend on x and atmospheric stability.

Dispersion coefficients are typically parameterized by stability classes (for example Pasquill-Gifford) or by more modern schemes, and they reflect how turbulence spreads the plume in the vertical and horizontal directions. GaussPlumeModelle assume steady, homogeneous wind, flat terrain, and a single source, which limits their applicability in complex terrains or rapidly changing conditions.

Applications include regulatory air-quality assessments, industrial hygiene, and preliminary impact studies. The GaussPlumeModel concept originated in mid-20th-century atmospheric science, with foundational contributions that shaped subsequent regulatory and computational models, while modern tools often extend or couple Gaussian plumes with puff models and Lagrangian frameworks for greater flexibility.