def test_annual_mb(self):
"""Test the routine computing the annual mass balance."""
# run all needed prepro tasks
gdir = self._setup_mb_test()
# get relevant glacier surface elevation
min_hgt, max_hgt = vascaling.get_min_max_elevation(gdir)
# define temporal range
year = 1975
years = np.array([year, year])
# get mass balance relevant climate data
_, temp, prcp = vascaling.get_yearly_mb_temp_prcp(gdir,
year_range=years)
temp = temp[0]
prcp = prcp[0]
# read mu* and bias from vascaling_mustar
vascaling_mustar = gdir.read_json('vascaling_mustar')
mu_star = vascaling_mustar['mu_star']
bias = vascaling_mustar['bias']
# specify scaling factor for SI units [kg s-1]
fac_SI = cfg.SEC_IN_YEAR * cfg.PARAMS['ice_density']
# compute mass balance 'by hand'
mb_ref = (prcp - mu_star * temp - bias) / fac_SI
# compute mb using the VAS mass balance model
mb_mod = vascaling.VAScalingMassBalance(gdir).get_annual_mb(min_hgt,
max_hgt,
year)
# compare mass balances with bias
np.testing.assert_allclose(mb_ref, mb_mod, rtol=1e-3)
# compute mass balance 'by hand'
mb_ref = (prcp - mu_star * temp) / fac_SI
# compute mb 'by model'
mb_mod = vascaling.VAScalingMassBalance(gdir, bias=0). \
get_annual_mb(min_hgt, max_hgt, year)
# compare mass balances without bias
np.testing.assert_allclose(mb_ref, mb_mod, rtol=1e-3)
def test_yearly_mb_temp_prcp(self):
"""Test the routine which returns the yearly mass balance relevant
climate parameters, i.e. positive melting temperature and solid
precipitation. The testing target is the output of the corresponding
OGGM routine `get_yearly_mb_climate_on_glacier(gdir)`.
"""
# read the Hintereisferner DEM
hef_file = get_demo_file('Hintereisferner_RGI5.shp')
entity = gpd.read_file(hef_file).iloc[0]
# initialize the GlacierDirectory
gdir = oggm.GlacierDirectory(entity, base_dir=self.testdir)
# define the local grid and glacier mask
gis.define_glacier_region(gdir, entity=entity)
gis.glacier_masks(gdir)
# run centerline prepro tasks
centerlines.compute_centerlines(gdir)
centerlines.initialize_flowlines(gdir)
centerlines.catchment_area(gdir)
centerlines.catchment_intersections(gdir)
centerlines.catchment_width_geom(gdir)
centerlines.catchment_width_correction(gdir)
# process the given climate file
climate.process_custom_climate_data(gdir)
# get yearly sums of terminus temperature and solid precipitation
years, temp, prcp = vascaling.get_yearly_mb_temp_prcp(gdir)
# use the OGGM methode to get the mass balance
# relevant climate parameters
years_oggm, temp_oggm, prcp_oggm = \
climate.mb_yearly_climate_on_glacier(gdir)
# the energy input at the glacier terminus must be greater than (or
# equal to) the glacier wide average, since the air temperature drops
# with elevation, i.e. the mean deviation must be positive, using the
# OGGM data as reference
assert md(temp_oggm, temp) >= 0
# consequentially, the average mass input must be less than (or equal
# to) the mass input integrated over the whole glacier surface, i.e.
# the mean deviation must be negative, using the OGGM data as reference
# TODO: does it actually?! And if so, why?! @ASK
assert md(prcp_oggm, prcp) <= 0
# correlation must be higher than set threshold
assert corrcoef(temp, temp_oggm) >= 0.94
assert corrcoef(prcp, prcp_oggm) >= 0.98
# get terminus temperature using the OGGM routine
fpath = gdir.get_filepath('gridded_data')
with ncDataset(fpath) as nc:
mask = nc.variables['glacier_mask'][:]
topo = nc.variables['topo'][:]
heights = np.array([np.min(topo[np.where(mask == 1)])])
years_height, temp_height, _ = \
climate.mb_yearly_climate_on_height(gdir, heights, flatten=False)
temp_height = temp_height[0]
# both time series must be equal
np.testing.assert_array_equal(temp, temp_height)
# get solid precipitation averaged over the glacier
# (not weighted with widths)
fls = gdir.read_pickle('inversion_flowlines')
heights = np.array([])
for fl in fls:
heights = np.append(heights, fl.surface_h)
years_height, _, prcp_height = \
climate.mb_yearly_climate_on_height(gdir, heights, flatten=True)
# correlation must be higher than set threshold
assert corrcoef(prcp, prcp_height) >= 0.99
# TODO: assert absolute values (or differences) of precipitation @ASK
# test exception handling of out of bounds time/year range
with self.assertRaises(climate.MassBalanceCalibrationError):
# start year out of bounds
year_range = [1500, 1980]
_, _, _ = vascaling.get_yearly_mb_temp_prcp(gdir,
year_range=year_range)
with self.assertRaises(climate.MassBalanceCalibrationError):
# end year oud of bounds
year_range = [1980, 3000]
_, _, _ = vascaling.get_yearly_mb_temp_prcp(gdir,
year_range=year_range)
with self.assertRaises(ValueError):
# get not N full years
t0 = datetime.datetime(1980, 1, 1)
t1 = datetime.datetime(1980, 3, 1)
time_range = [t0, t1]
_, _, _ = vascaling.get_yearly_mb_temp_prcp(gdir,
time_range=time_range)
# TODO: assert gradient in climate file?!
pass
