"""
mfchd module. Contains the ModflowChd class. Note that the user can access
the ModflowChd class as `flopy.modflow.ModflowChd`.
Additional information for this MODFLOW package can be found at the `Online
MODFLOW Guide
<http://water.usgs.gov/ogw/modflow-nwt/MODFLOW-NWT-Guide/chd.htm>`_.
"""
import numpy as np
from ..pakbase import Package
from ..utils import MfList
from ..utils.recarray_utils import create_empty_recarray
[docs]class ModflowChd(Package):
"""
MODFLOW Constant Head Package Class.
Parameters
----------
model : model object
The model object (of type :class:`flopy.modflow.mf.Modflow`) to which
this package will be added.
stress_period_data : list of boundaries, recarrays, or dictionary of
boundaries.
Each chd cell is defined through definition of
layer (int), row (int), column (int), shead (float), ehead (float)
shead is the head at the start of the stress period, and ehead is the
head at the end of the stress period.
The simplest form is a dictionary with a lists of boundaries for each
stress period, where each list of boundaries itself is a list of
boundaries. Indices of the dictionary are the numbers of the stress
period. This gives the form of::
stress_period_data =
{0: [
[lay, row, col, shead, ehead],
[lay, row, col, shead, ehead],
[lay, row, col, shead, ehead]
],
1: [
[lay, row, col, shead, ehead],
[lay, row, col, shead, ehead],
[lay, row, col, shead, ehead]
], ...
kper:
[
[lay, row, col, shead, ehead],
[lay, row, col, shead, ehead],
[lay, row, col, shead, ehead]
]
}
Note that if the number of lists is smaller than the number of stress
periods, then the last list of chds will apply until the end of the
simulation. Full details of all options to specify stress_period_data
can be found in the flopy3 boundaries Notebook in the basic
subdirectory of the examples directory.
extension : string
Filename extension (default is 'chd')
unitnumber : int
File unit number (default is None).
filenames : str or list of str
Filenames to use for the package. If filenames=None the package name
will be created using the model name and package extension. If a
single string is passed the package will be set to the string.
Default is None.
Attributes
----------
mxactc : int
Maximum number of chds for all stress periods. This is calculated
automatically by FloPy based on the information in
stress_period_data.
Methods
-------
See Also
--------
Notes
-----
Parameters are supported in Flopy only when reading in existing models.
Parameter values are converted to native values in Flopy and the
connection to "parameters" is thus nonexistent.
Examples
--------
>>> import flopy
>>> m = flopy.modflow.Modflow()
>>> lrcd = {0:[[2, 3, 4, 10., 10.1]]} #this chd will be applied to all
>>> #stress periods
>>> chd = flopy.modflow.ModflowChd(m, stress_period_data=lrcd)
"""
def __init__(
self,
model,
stress_period_data=None,
dtype=None,
options=None,
extension="chd",
unitnumber=None,
filenames=None,
**kwargs,
):
# set default unit number if one is not specified
if unitnumber is None:
unitnumber = ModflowChd._defaultunit()
# call base package constructor
super().__init__(
model,
extension=extension,
name=self._ftype(),
unit_number=unitnumber,
filenames=self._prepare_filenames(filenames),
)
self.url = "chd.htm"
self._generate_heading()
if dtype is not None:
self.dtype = dtype
else:
self.dtype = self.get_default_dtype(
structured=self.parent.structured
)
self.stress_period_data = MfList(self, stress_period_data)
self.np = 0
if options is None:
options = []
self.options = options
self.parent.add_package(self)
def _ncells(self):
"""Maximum number of cells that have constant heads (developed for
MT3DMS SSM package).
Returns
-------
ncells: int
maximum number of chd cells
"""
return self.stress_period_data.mxact
[docs] def write_file(self):
"""
Write the package file.
Returns
-------
None
"""
f_chd = open(self.fn_path, "w")
f_chd.write(f"{self.heading}\n")
f_chd.write(f" {self.stress_period_data.mxact:9d}")
for option in self.options:
f_chd.write(" {}".format(option))
f_chd.write("\n")
self.stress_period_data.write_transient(f_chd)
f_chd.close()
[docs] def add_record(self, kper, index, values):
try:
self.stress_period_data.add_record(kper, index, values)
except Exception as e:
raise Exception(f"mfchd error adding record to list: {e!s}")
[docs] @staticmethod
def get_empty(ncells=0, aux_names=None, structured=True):
# get an empty recarray that corresponds to dtype
dtype = ModflowChd.get_default_dtype(structured=structured)
if aux_names is not None:
dtype = Package.add_to_dtype(dtype, aux_names, np.float32)
return create_empty_recarray(ncells, dtype, default_value=-1.0e10)
[docs] @staticmethod
def get_default_dtype(structured=True):
if structured:
dtype = np.dtype(
[
("k", int),
("i", int),
("j", int),
("shead", np.float32),
("ehead", np.float32),
]
)
else:
dtype = np.dtype(
[
("node", int),
("shead", np.float32),
("ehead", np.float32),
]
)
return dtype
@staticmethod
def _get_sfac_columns():
return ["shead", "ehead"]
[docs] @classmethod
def load(cls, f, model, nper=None, ext_unit_dict=None, check=True):
"""
Load an existing package.
Parameters
----------
f : filename or file handle
File to load.
model : model object
The model object (of type :class:`flopy.modflow.mf.Modflow`) to
which this package will be added.
nper : int
The number of stress periods. If nper is None, then nper will be
obtained from the model object. (default is None).
ext_unit_dict : dictionary, optional
If the arrays in the file are specified using EXTERNAL,
or older style array control records, then `f` should be a file
handle. In this case ext_unit_dict is required, which can be
constructed using the function
:class:`flopy.utils.mfreadnam.parsenamefile`.
Returns
-------
chd : ModflowChd object
ModflowChd object.
Examples
--------
>>> import flopy
>>> m = flopy.modflow.Modflow()
>>> wel = flopy.modflow.ModflowChd.load('test.chd', m)
"""
if model.verbose:
print("loading chd package file...")
return Package.load(
f,
model,
cls,
nper=nper,
check=check,
ext_unit_dict=ext_unit_dict,
)
@staticmethod
def _ftype():
return "CHD"
@staticmethod
def _defaultunit():
return 24