pydune.physics.quartic_transport_law#

quartic_transport_law(theta, theta_d, Kappa=0.4, mu=0.63, cm=1.7)[source]#

Quartic transport law \(q_{\rm sat}/Q = \frac{2\sqrt{\theta_{\rm th}}}{\kappa\mu}(\theta - \theta_{\rm th})\left[1 + \frac{C_{\rm M}}{\mu}(\theta - \theta_{\rm th})\right]\) from Pähtz et al. 2020.

Parameters:

  • theta (scalar, numpy array) – Shield number.

  • theta_d (scalar, numpy array) – Threshold Shield number.

  • Kappa (scalar, numpy array) – von Kármán constant (the default is 0.4).

  • mu (scalar, numpy array) – Friction coefficient (the default is 0.63).

  • cm (scalar, numpy array) – Transport law coefficient (the default is 1.7).

Returns:

Sediment fluxes calculated elementwise using the quartic transport law.

Return type:

scalar, numpy array

Examples

>>> import numpy as np
>>> theta = np.random.random((2000, ))
>>> theta_d = 0.0035
>>> qsat = quartic_transport_law(theta, theta_d)

References

[1] Pähtz, T., & Durán, O. (2020). Unification of aeolian and fluvial sediment transport rate from granular physics. Physical review letters, 124(16), 168001.

Examples using pydune.physics.quartic_transport_law#

Fitting transport laws

Fitting transport laws

From wind data to sand fluxes and dune orientations

From wind data to sand fluxes and dune orientations