Hantush¶

class Hantush(up=False, meanstress=1, cutoff=0.999)[source]¶

The Hantush well function, using the standard A, a, b parameters

Parameters

up (bool or None, optional) – indicates whether a positive stress will cause the head to go up (True, default) or down (False), if None the head can go both ways.
meanstress (float) – mean value of the stress, used to set the initial value such that the final step times the mean stress equals 1
cutoff (float) – proportion after which the step function is cut off. default is 0.999.

Notes

The Hantush well function is explained in [hantush_1955], [veling_2010] and [asmuth_2008]. The impulse response function may be written as:

\[\theta(t) = \frac{A}{t} \exp(-t/a - ab/t)\]

\[p[0] = A = \frac{1}{2 \pi T}\]

\[p[1] = a = cS\]

\[p[2] = b = r^2 / (4 \lambda^2)\]

where \(\lambda = \sqrt{Tc}\)

References

hantush_1955: Hantush, M. S., & Jacob, C. E. (1955). Non‐steady radial flow in an infinite leaky aquifer. Eos, Transactions American Geophysical Union, 36(1), 95-100.
veling_2010: Veling, E. J. M., & Maas, C. (2010). Hantush well function revisited. Journal of hydrology, 393(3), 381-388.
asmuth_2008: Von Asmuth, J. R., Maas, K., Bakker, M., & Petersen, J. (2008). Modeling time series of ground water head fluctuations subjected to multiple stresses. Ground Water, 46(1), 30-40.

Methods¶

`__init__`
`block`	Method to return the block function.
`gain`
`get_init_parameters`	Get initial parameters and bounds.
`get_t`	Internal method to determine the times at which to evaluate the step-response, from t=0
`get_tmax`	Method to get the response time for a certain cutoff
`step`	Method to return the step function.