This page was generated from shapefile_export_example.py. It's also available as a notebook.

Shapefile export demo

The goal of this notebook is to demonstrate ways to export model information to shapefiles. This example will cover: * basic exporting of information for a model, individual package, or dataset * custom exporting of combined data from different packages * general exporting and importing of geographic data from other sources

import os

import sys
from tempfile import TemporaryDirectory

import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd

import flopy

print(sys.version)
print(f"numpy version: {np.__version__}")
print(f"matplotlib version: {mpl.__version__}")
print(f"flopy version: {flopy.__version__}")

3.8.18 (default, Aug 28 2023, 08:27:22)
[GCC 11.4.0]
numpy version: 1.24.4
matplotlib version: 3.7.4
flopy version: 3.6.0

# temporary directory
temp_dir = TemporaryDirectory()
outdir = os.path.join(temp_dir.name, "shapefile_export")

# load an existing model
model_ws = "../../examples/data/freyberg"
m = flopy.modflow.Modflow.load(
    "freyberg.nam",
    model_ws=model_ws,
    verbose=False,
    check=False,
    exe_name="mfnwt",
)

m.get_package_list()

['DIS', 'BAS6', 'LPF', 'WEL', 'RIV', 'RCH', 'OC', 'PCG']

set the model coordinate information

the coordinate information where the grid is located in a projected coordinate system (e.g. UTM)

grid = m.modelgrid
grid.set_coord_info(xoff=273170, yoff=5088657, crs=26916)

grid.extent

(273170.0, 278170.0, 5088657.0, 5098657.0)

Declarative export using attached .export() methods

Export the whole model to a single shapefile

fname = f"{outdir}/model.shp"
m.export(fname)

/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for delc array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for delr array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for laycbd array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for nstp array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for perlen array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for steady array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for tsmult array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for chani array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for layavg array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for laytyp array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for layvka array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for laywet array, LPF package
  warn(

ax = plt.subplot(1, 1, 1, aspect="equal")
extents = grid.extent
pc = flopy.plot.plot_shapefile(fname, ax=ax, edgecolor="k", facecolor="none")
ax.set_xlim(extents[0], extents[1])
ax.set_ylim(extents[2], extents[3])
ax.set_title(fname)

Text(0.5, 1.0, '/tmp/tmpqcjxixbo/shapefile_export/model.shp')

fname = f"{outdir}/wel.shp"
m.wel.export(fname)

Export a package to a shapefile

Export a FloPy list or array object

m.lpf.hk

<flopy.utils.util_array.Util3d at 0x7f5f732778e0>

fname = f"{outdir}/hk.shp"
m.lpf.hk.export(f"{outdir}/hk.shp")

ax = plt.subplot(1, 1, 1, aspect="equal")
extents = grid.extent
a = m.lpf.hk.array.ravel()
pc = flopy.plot.plot_shapefile(fname, ax=ax, a=a)
ax.set_xlim(extents[0], extents[1])
ax.set_ylim(extents[2], extents[3])
ax.set_title(fname)

Text(0.5, 1.0, '/tmp/tmpqcjxixbo/shapefile_export/hk.shp')

m.riv.stress_period_data

<flopy.utils.util_list.MfList at 0x7f5f73290430>

m.riv.stress_period_data.export(f"{outdir}/riv_spd.shp")

MfList.export() exports the whole grid by default, regardless of the locations of the boundary cells

sparse=True only exports the boundary cells in the MfList

m.riv.stress_period_data.export(f"{outdir}/riv_spd.shp", sparse=True)

m.wel.stress_period_data.export(f"{outdir}/wel_spd.shp", sparse=True)

Ad-hoc exporting using recarray2shp

• The main idea is to create a recarray with all of the attribute information, and a list of geometry features (one feature per row in the recarray)

• each geometry feature is an instance of the Point, LineString or Polygon classes in flopy.utils.geometry. The shapefile format requires all the features to be of the same type.

• We will use pandas dataframes for these examples because they are easy to work with, and then convert them to recarrays prior to exporting.

from flopy.export.shapefile_utils import recarray2shp

combining data from different packages

write a shapefile of RIV and WEL package cells

wellspd = pd.DataFrame(m.wel.stress_period_data[0])
rivspd = pd.DataFrame(m.riv.stress_period_data[0])
spd = pd.concat([wellspd, rivspd])
spd.head()

	k	i	j	flux	iface	stage	cond	rbot
0	0	8	15	-0.00820	0.0	NaN	NaN	NaN
1	0	10	12	-0.00410	0.0	NaN	NaN	NaN
2	0	19	13	-0.00390	0.0	NaN	NaN	NaN
3	0	25	9	-0.00083	0.0	NaN	NaN	NaN
4	0	28	5	-0.00072	0.0	NaN	NaN	NaN

from flopy.utils.geometry import Polygon

vertices = []
for row, col in zip(spd.i, spd.j):
    vertices.append(grid.get_cell_vertices(row, col))
polygons = [Polygon(vrt) for vrt in vertices]
polygons

[<flopy.utils.geometry.Polygon at 0x7f5f72aef1f0>,
 <flopy.utils.geometry.Polygon at 0x7f5f72aef5e0>,
 <flopy.utils.geometry.Polygon at 0x7f5f72aef940>,
 <flopy.utils.geometry.Polygon at 0x7f5f72aefca0>,
 <flopy.utils.geometry.Polygon at 0x7f5f72aefee0>,
 <flopy.utils.geometry.Polygon at 0x7f5f72aefe80>,
 <flopy.utils.geometry.Polygon at 0x7f5f72aefc10>,
 <flopy.utils.geometry.Polygon at 0x7f5f72aefa90>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99730>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99040>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a992b0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99340>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a993d0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a993a0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a994c0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99580>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a996a0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99610>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99700>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99790>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a998b0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99940>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99a00>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99af0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99b20>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99c10>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99d60>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99d30>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99e80>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99e50>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99fa0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99f70>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99160>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99070>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99970>,
 <flopy.utils.geometry.Polygon at 0x7f5f70a99c40>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9280>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9310>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab93a0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9460>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab94f0>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9580>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9670>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9700>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9790>,
 <flopy.utils.geometry.Polygon at 0x7f5f70ab9820>]

fname = f"{outdir}/bcs.shp"
recarray2shp(spd.to_records(), geoms=polygons, shpname=fname, crs=grid.epsg)

ax = plt.subplot(1, 1, 1, aspect="equal")
extents = grid.extent
pc = flopy.plot.plot_shapefile(fname, ax=ax)
ax.set_xlim(extents[0], extents[1])
ax.set_ylim(extents[2], extents[3])
ax.set_title(fname)

Text(0.5, 1.0, '/tmp/tmpqcjxixbo/shapefile_export/bcs.shp')

exporting other data

Suppose we have some well data with actual locations that we want to export to a shapefile

welldata = pd.DataFrame(
    {
        "wellID": np.arange(0, 10),
        "q": np.random.randn(10) * 100 - 1000,
        "x_utm": np.random.rand(10) * 5000 + grid.xoffset,
        "y_utm": grid.yoffset + np.random.rand(10) * 10000,
    }
)
welldata.head()

	wellID	q	x_utm	y_utm
0	0	-855.292275	276113.912383	5.092184e+06
1	1	-1220.241824	274276.956977	5.093778e+06
2	2	-1125.180973	277528.392419	5.092315e+06
3	3	-1013.527988	274016.114893	5.092242e+06
4	4	-1093.973543	276451.585512	5.089133e+06

from flopy.utils.geometry import Point

geoms = [Point(x, y) for x, y in zip(welldata.x_utm, welldata.y_utm)]

fname = f"{outdir}/wel_data.shp"
recarray2shp(welldata.to_records(), geoms=geoms, shpname=fname, crs=grid.epsg)

ax = plt.subplot(1, 1, 1, aspect="equal")
extents = grid.extent
pc = flopy.plot.plot_shapefile(fname, ax=ax, radius=100)
ax.set_xlim(extents[0], extents[1])
ax.set_ylim(extents[2], extents[3])
ax.set_title(fname)

Text(0.5, 1.0, '/tmp/tmpqcjxixbo/shapefile_export/wel_data.shp')

Adding attribute data to an existing shapefile

Suppose we have a GIS coverage representing the river in the riv package

from flopy.utils.geometry import LineString

### make up a linestring shapefile of the river reaches
i, j = m.riv.stress_period_data[0].i, m.riv.stress_period_data[0].j
x0 = grid.xyzcellcenters[0][i[0], j[0]]
x1 = grid.xyzcellcenters[0][i[-1], j[-1]]
y0 = grid.xyzcellcenters[1][i[0], j[0]]
y1 = grid.xyzcellcenters[1][i[-1], j[-1]]
x = np.linspace(x0, x1, m.nrow + 1)
y = np.linspace(y0, y1, m.nrow + 1)
l0 = zip(list(zip(x[:-1], y[:-1])), list(zip(x[1:], y[1:])))
lines = [LineString(l) for l in l0]

rivdata = pd.DataFrame(m.riv.stress_period_data[0])
rivdata["reach"] = np.arange(len(lines))
lines_shapefile = f"{outdir}/riv_reaches.shp"
recarray2shp(
    rivdata.to_records(index=False),
    geoms=lines,
    shpname=lines_shapefile,
    crs=grid.epsg,
)

ax = plt.subplot(1, 1, 1, aspect="equal")
extents = grid.extent
pc = flopy.plot.plot_shapefile(lines_shapefile, ax=ax, radius=25)
ax.set_xlim(extents[0], extents[1])
ax.set_ylim(extents[2], extents[3])
ax.set_title(lines_shapefile)

Text(0.5, 1.0, '/tmp/tmpqcjxixbo/shapefile_export/riv_reaches.shp')

shp2recarray reads a shapefile into a numpy record array, which can easily be converted to a DataFrame

from flopy.export.shapefile_utils import shp2recarray

linesdata = shp2recarray(lines_shapefile)
linesdata = pd.DataFrame(linesdata)
linesdata.head()

	k	i	j	stage	cond	rbot	iface	reach	geometry
0	0	0	14	20.100000	0.05	20.00	0.0	0	<flopy.utils.geometry.LineString object at 0x7...
1	0	1	14	19.870001	0.05	19.75	0.0	1	<flopy.utils.geometry.LineString object at 0x7...
2	0	2	14	19.650000	0.05	19.50	0.0	2	<flopy.utils.geometry.LineString object at 0x7...
3	0	3	14	19.420000	0.05	19.25	0.0	3	<flopy.utils.geometry.LineString object at 0x7...
4	0	4	14	19.190001	0.05	19.00	0.0	4	<flopy.utils.geometry.LineString object at 0x7...

# make up some fluxes between the river and aquifer at each reach
q = np.random.randn(len(linesdata)) + 1
q

array([-0.53939247,  0.41561731,  0.48356253,  3.29123291,  1.55125836,
        0.3737809 ,  1.54142589,  1.67407573,  0.07921016, -0.03956503,
        1.08509722,  0.55505263, -0.05057926,  2.23448414,  1.46246758,
        1.3823466 , -0.28641713,  0.69402634,  1.31150842, -0.00375265,
       -1.05756663, -0.9362195 ,  2.04507458,  1.35794523,  0.22037462,
        0.47525421, -0.22621915,  3.53071552,  1.82628426, -0.15855462,
       -0.46807587, -0.34459139,  1.87156536, -0.23335179,  1.33285549,
       -1.09098118,  1.53239348,  0.33789905,  0.61399906,  0.6026606 ])

linesdata["qreach"] = q
linesdata["qstream"] = np.cumsum(q)

recarray2shp(
    linesdata.drop("geometry", axis=1).to_records(),
    geoms=linesdata.geometry.values,
    shpname=lines_shapefile,
    crs=grid.epsg,
)

ax = plt.subplot(1, 1, 1, aspect="equal")
extents = grid.extent
pc = flopy.plot.plot_shapefile(lines_shapefile, ax=ax, radius=25)
ax.set_xlim(extents[0], extents[1])
ax.set_ylim(extents[2], extents[3])
ax.set_title(lines_shapefile)

Text(0.5, 1.0, '/tmp/tmpqcjxixbo/shapefile_export/riv_reaches.shp')

Overriding the model’s modelgrid with a user supplied modelgrid

In some cases it may be necessary to override the model’s modelgrid instance with a seperate modelgrid. An example of this is if the model discretization is in feet and the user would like it projected in meters. Exporting can be accomplished by supplying a modelgrid as a kwarg in any of the export() methods within flopy. Below is an example:

mg0 = m.modelgrid

# build a new modelgrid instance with discretization in meters
modelgrid = flopy.discretization.StructuredGrid(
    delc=mg0.delc * 0.3048,
    delr=mg0.delr * 0.3048,
    top=mg0.top,
    botm=mg0.botm,
    idomain=mg0.idomain,
    xoff=mg0.xoffset * 0.3048,
    yoff=mg0.yoffset * 0.3048,
)

# exporting an entire model
m.export(f"{outdir}/freyberg.shp", modelgrid=modelgrid)

No CRS information for writing a .prj file.
Supply an valid coordinate system reference to the attached modelgrid object or .export() method.
No CRS information for writing a .prj file.
Supply an valid coordinate system reference to the attached modelgrid object or .export() method.

/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for delc array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for delr array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for laycbd array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for nstp array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for perlen array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for steady array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for tsmult array, DIS package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for chani array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for layavg array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for laytyp array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for layvka array, LPF package
  warn(
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/flopy/export/shapefile_utils.py:319: UserWarning: Failed to get data for laywet array, LPF package
  warn(

And for a specific parameter the method is the same

fname = f"{outdir}/hk.shp"
m.lpf.hk.export(fname, modelgrid=modelgrid)

No CRS information for writing a .prj file.
Supply an valid coordinate system reference to the attached modelgrid object or .export() method.

ax = plt.subplot(1, 1, 1, aspect="equal")
extents = modelgrid.extent
a = m.lpf.hk.array.ravel()
pc = flopy.plot.plot_shapefile(fname, ax=ax, a=a)
ax.set_xlim(extents[0], extents[1])
ax.set_ylim(extents[2], extents[3])
ax.set_title(fname)

Text(0.5, 1.0, '/tmp/tmpqcjxixbo/shapefile_export/hk.shp')

try:
    # ignore PermissionError on Windows
    temp_dir.cleanup()
except:
    pass