Surface water network
Creates surface water network, which can be used to create MODFLOW's SFR.
Python packages
Python 3.6+ is required.
Required
geopandas
- process spatial data similar to pandaspyproj>=2.2
- spatial projection supportrtree
- spatial index support
Optional
flopy
- read/write MODFLOW modelsnetCDF4
- used to read TopNet files
Testing
Run pytest -v
or python3 -m pytest -v
For faster multi-core pytest -v -n 2
(with pytest-xdist
)
Examples
import geopandas
import pandas as pd
import swn
import swn.file
Read from Shapefile:
shp_srs = 'tests/data/DN2_Coastal_strahler1z_stream_vf.shp'
lines = geopandas.read_file(shp_srs)
lines.set_index('nzsegment', inplace=True, verify_integrity=True) # optional
Or, read from PostGIS:
from sqlalchemy import create_engine, engine
con_url = engine.url.URL(drivername='postgresql', database='scigen')
con = create_engine(con_url)
sql = 'SELECT * FROM wrc.rec2_riverlines_coastal'
lines = geopandas.read_postgis(sql, con)
lines.set_index('nzsegment', inplace=True, verify_integrity=True) # optional
Initialise and create network:
n = swn.SurfaceWaterNetwork.from_lines(lines.geometry)
print(n)
#
# 304 segments: [3046409, 3046455, ..., 3050338, 3050418]
# 154 headwater: [3046409, 3046542, ..., 3050338, 3050418]
# 3 outlets: [3046700, 3046737, 3046736]
# no diversions />
Plot the network, write a Shapefile, write and read a SurfaceWaterNetwork file:
n.plot()
swn.file.gdf_to_shapefile(n.segments, 'segments.shp')
n.to_pickle('network.pkl')
n = swn.SurfaceWaterNetwork.from_pickle('network.pkl')
Remove segments that meet a condition (stream order), or that are upstream/downstream from certain locations:
n.remove(n.segments.stream_order == 1, segnums=n.query(upstream=3047927))
Read flow data from a TopNet netCDF file, convert from m3/s to m3/day:
nc_path = 'tests/data/streamq_20170115_20170128_topnet_03046727_strahler1.nc'
flow = swn.file.topnet2ts(nc_path, 'mod_flow', 86400)
# remove time and truncate to closest day
flow.index = flow.index.floor('d')
# 7-day mean
flow7d = flow.resample('7D').mean()
# full mean
flow_m = pd.DataFrame(flow.mean(0)).T
Process a MODFLOW/flopy model:
import flopy
m = flopy.modflow.Modflow.load('h.nam', model_ws='tests/data', check=False)
nm = swn.SwnModflow.from_swn_flopy(n, m)
nm.default_segment_data()
nm.set_segment_data_inflow(flow_m)
nm.plot()
nm.to_pickle('sfr_network.pkl')
nm = swn.SwnModflow.from_pickle('sfr_network.pkl', n, m)
nm.set_sfr_obj()
m.sfr.write_file('file.sfr')
nm.grid_cells.to_file('grid_cells.shp')
nm.reaches.to_file('reaches.shp')
Citation
Toews, M. W.; Hemmings, B. 2019. A surface water network method for generalising streams and rapid groundwater model development. In: New Zealand Hydrological Society Conference, Rotorua, 3-6 December, 2019. p. 166-169.