Metadata-Version: 2.4
Name: NFBM
Version: 0.2.0
Summary: Neuman Flux Boundary Model
Author: Bas de Ridder
Requires-Python: >=3.9
Description-Content-Type: text/markdown
Requires-Dist: numpy
Requires-Dist: mpmath

# NFBM

**Neuman–Flux Boundary Model**

NFBM is a Python implementation and extension of the analytical solution presented by Neuman (1974) for delayed-yield groundwater flow in unconfined aquifers.

The model introduces two additional boundary-condition (parameters):

* **R** — finite aquifer radius [L]

  Represents the lateral extent of the aquifer and can be used to simulate the influence of nearby open-water boundaries such as ditches, canals, or lakes.

* **q** — change in vertical flux [L/T]

  Represents a change in upward or downward flux from an underlying aquifer induced by pumping. The background flux is assumed to be present before pumping starts; only the change in flux caused by drawdown is simulated.

## Features

* Delayed-yield response following Neuman's analytical solution.
* Finite-radius aquifer boundary condition (`R`).
* Vertical flux-change boundary condition (`q`).
* Numerical inversion of the Laplace transform using the de Hoog algorithm.
* Suitable for pumping-test analysis in shallow unconfined aquifers and peatlands.

## Units

NFBM does not enforce a specific unit system. However, **all input parameters must be provided in a consistent set of units**.

For example:

| Parameter                                      | Example Unit |
| ---------------------------------------------- | ------------ |
| Distance (`r`, `R`, `b`, `d`, `l`, `z1`, `z2`) | m            |
| Time (`t`)                                     | d            |
| Hydraulic conductivity (`k`)                   | m/d          |
| Specific storage (`Ss`)                        | 1/m          |
| Specific yield (`Sy`)                          | -            |
| Pumping rate (`Q`)                             | m³/d         |
| Flux change (`q`)                              | m/d          |

A recommended unit system is **meters (m)** and **days (d)**.

## References

Neuman, S. P. (1974). Effect of partial penetration on flow in unconfined aquifers considering delayed
gravity response. Water Resources Research, 10(2), 303–312. https://doi.org/10.1029/WR010i002p00303
