grf(time, rad, storage, conductivity, dim=2, lat_ext=1.0, rate=-0.0001, r_well=0.0, r_bound=inf, h_bound=0.0, struc_grid=True, lap_kwargs=None)[source]

The general radial flow (GRF) model for a pumping test.

This solution was presented in [Barker88].

  • time (numpy.ndarray) – Array with all time-points where the function should be evaluated.

  • rad (numpy.ndarray) – Array with all radii where the function should be evaluated.

  • storage (float) – Storage coefficient of the aquifer.

  • conductivity (float) – Conductivity of the aquifer.

  • dim (float, optional) – Fractional dimension of the aquifer. Default: 2.0

  • lat_ext (float, optional) – Lateral extend of the aquifer. Default: 1.0

  • rate (float, optional) – Pumpingrate at the well. Default: -1e-4

  • r_well (float, optional) – Inner radius of the pumping-well. Default: 0.0

  • r_bound (float, optional) – Radius of the outer boundary of the aquifer. Default: np.inf

  • h_bound (float, optional) – Reference head at the outer boundary, as well as initial condition. Default: 0.0

  • struc_grid (bool, optional) – If this is set to “False”, the “rad” and “time” array will be merged and interpreted as single, r-t points. In this case they need to have the same shapes. Otherwise a structured r-t grid is created. Default: True

  • lap_kwargs (dict or None optional) – Dictionary for get_lap_inv containing method and method_dict. The default is equivalent to lap_kwargs = {"method": "stehfest", "method_dict": None}. Default: None


head – Array with all heads at the given radii and time-points.

Return type




Barker, J. ‘’A generalized radial flow model for hydraulic tests in fractured rock.’’, Water Resources Research 24.10, 1796-1804, 1988