# extracted files
gagepath = '{}/gagedata'.format(directory) # all HUC8 NWIS flow data path
# time series start and end
start = datetime.datetime(1980, 1, 1) # start date for timeseries
end = datetime.datetime(2010, 1, 1) # end date for timeseries
# create an instance of the NWIS extractor
nwisextractor = NWISExtractor(NWIS)
# extract the locations of the gage stations in the HUC8 (Patuxent watershed)
# into a new shapefile
nwisextractor.extract_HUC8(HUC8, directory)
# and download all the daily flow and water quality data across the period
# for the gages in the gage shapefile
if not os.path.isdir(gagepath):
nwisextractor.download_all(start, end, output = gagepath)
# alternatively, download the daily flow and water quality data for one gage
# given the USGS NWIS Site ID number (Hunting Creek)
gageid = '01594670'
gagedata = 'hunting_station'
nwisextractor.download_gagedata(gageid, start, end, output = gagedata)
print('Please ensure that the file {} exists\n'.format(flowfile))
raise
# create an instance of the NWISExtractor to use to download the gage data
extractor = NWISExtractor(NWIS)
# download the metadata for all NWIS gages (will be skipped if it exists)
extractor.download_metadata()
# download all the data for the gage, including measured values of stage,
# discharge, channel width, and channel area and save it to "gageid" file
# (will be skipped if it already exists)
extractor.download_gagedata(gageid, start, end, output=gageidpath)
# need to know the reach length; so find the location of the gage, then find
# the flowline in the shapefile and use the record info to get the length
# first use the NWIS metadata file to get the latitude and longitude of the gage
reader = Reader('{}/USGS_Streamgages-NHD_Locations.shp'.format(NWIS))
# find the record index for the NWIS gage ids
i = [f[0] for f in reader.fields].index('SITE_NO') - 1
# find the index of the gage
j = [r[i] for r in reader.records()].index(gageid)
# into a new shapefile
nwisextractor.extract_HUC8(HUC8, directory)
# and download all the daily flow and water quality data across the period
# for the gages in the gage shapefile
if not os.path.isdir(gagepath):
nwisextractor.download_all(start, end, output = gagepath)
# alternatively, download the daily flow and water quality data for one gage
# given the USGS NWIS Site ID number (Hunting Creek)
gageid = '01594670'
gagedata = 'hunting_station'
nwisextractor.download_gagedata(gageid, start, end, output = gagedata)
# the output directory will contain images with flow-duration curves and
# daily flow hydrographs. the statements below show how to access the data
# from the downloaded files. let's open up the data files from the patuxent
# directory that was made above.
print('fetching flow data from the Patuxent watershed')
# make a list of all the data files just downloaded
datafiles = [f for f in os.listdir(gagepath) if f[-3:] != 'png']
# iterate through the list, get/print some data for each gage
print('Data for downloaded stations:')
def extract():
"""Create an extract function to call from at runtime and to turn off
the extraction steps when they are done."""
# create an instance of the NWIS extractor
nwisextractor = NWISExtractor(NWIS)
# download and decompress the source metadata files
nwisextractor.download_metadata()
# extract all the gage stations and metadata into a shapefile for the HUC8
nwisextractor.extract_HUC8(HUC8, output)
# tell the extractor to use the metadata file above to find gage data
nwisextractor.set_metadata(gagefile)
# create an instance of the NHDPlus extractor
nhdplusextractor = NHDPlusExtractor(drainid, VPU, NHDPlus)
# download and decompress the source data for the Mid Atlantic Region
nhdplusextractor.download_data()
# extract the HUC8 data for the Patuxent watershed
nhdplusextractor.extract_HUC8(HUC8, output)
# create an instance of the NHDPlusDelineator to use to build the Watershed
delineator = NHDPlusDelineator(VAAfile,
flowfile,
catchfile,
elevfile,
gagefile=gagefile)
# delineate the watershed (extract the flowlines, catchments and other data)
delineator.delineate_gage_watershed(gage, output=gagepath)
# download the daily flow and water quality data for the gage
nwisextractor.download_gagedata(gage, estart, eend, output=gagedata)
# open the NWIS flow data for the Hunting Creek gage station
with open(gagedata, 'rb') as f:
station = pickle.load(f)
# get the time series of daily flow values for the gage
flow = station.make_timeseries(estart, eend)
# add land use data from 1988 to the delineator
delineator.add_basin_landuse(1988, landuse)
# build the watershed
delineator.build_gage_watershed(gage, watershed, masslinkplot=masslink)
