# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2014-2021 GEM Foundation
#
# OpenQuake is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OpenQuake is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
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# You should have received a copy of the GNU Affero General Public License
# along with OpenQuake. If not, see <http://www.gnu.org/licenses/>.
"""
Module exports :class:`KothaEtAl2016`,
:class:`KothaEtAl2016Italy`,
:class:`KothaEtAl2016Turkey`,
:class:`KothaEtAl2016Others`,
"""
import os
import numpy as np
from scipy.constants import g
from openquake.hazardlib.gsim.base import GMPE, CoeffsTable
from openquake.hazardlib import const
from openquake.hazardlib.imt import PGA, PGV, SA
KOTHA_CSV = os.path.join(os.path.dirname(__file__), 'kotha_2016.csv')
CONSTS = {"Mh": 6.75, "Mref": 5.5, "Rref": 1.0}
def _get_anelastic_coeff(kind, C):
"""
This function is a regionalisable parameter - will be modified in
other classes
"""
if kind == "base":
return C["c3"]
elif kind == "ITA":
return C["c3"] + C["Dc3IT"]
elif kind == "TUR":
return C["c3"] + C["Dc3TR"]
elif kind == "other":
return C["c3"] + C["Dc3OTH"]
def _get_distance_term(kind, C, rjb, mag):
"""
Returns the general distance scaling term - equation 2
"""
c_3 = _get_anelastic_coeff(kind, C)
rval = np.sqrt(rjb ** 2. + C["h"] ** 2.)
return (C["c1"] + C["c2"] * (mag - CONSTS["Mref"])) *\
np.log(rval / CONSTS["Rref"]) +\
c_3 * (rval - CONSTS["Rref"])
def _get_magnitude_term(C, mag):
"""
Returns the magnitude scaling term - equation 3
"""
if mag >= CONSTS["Mh"]:
return C["e1"] + C["b3"] * (mag - CONSTS["Mh"])
else:
return C["e1"] + (C["b1"] * (mag - CONSTS["Mh"])) +\
(C["b2"] * (mag - CONSTS["Mh"]) ** 2.)
def _get_regional_site_term(kind, C):
"""
Region specific site term - modified in subclasses
"""
if kind == "base":
return 0., 0.
elif kind == "ITA":
return C["Dg1IT"], C["Dg2IT"]
elif kind == "TUR":
return C["Dg1TR"], C["Dg2TR"]
elif kind == "other":
return C["Dg1OTH"], C["Dg2OTH"]
def _get_site_term(kind, C, vs30):
"""
Returns only a linear site amplification term
"""
dg1, dg2 = _get_regional_site_term(kind, C)
return (C["g1"] + dg1) + (C["g2"] + dg2) * np.log(vs30)
[docs]class KothaEtAl2016(GMPE):
"""
Implements unregionalised form of the European GMPE of:
Kotha, S. R., Bindi, D. and Cotton, F. (2016) "Partially non-ergodic
region specific GMPE for Europe and the Middle-East", Bull. Earthquake Eng.
14: 1245 - 1263
"""
#: Supported tectonic region type is 'active shallow crust'
DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.ACTIVE_SHALLOW_CRUST
#: Set of :mod:`intensity measure types <openquake.hazardlib.imt>`
#: this GSIM can calculate. A set should contain classes from module
#: :mod:`openquake.hazardlib.imt`.
DEFINED_FOR_INTENSITY_MEASURE_TYPES = {PGA, PGV, SA}
#: Supported intensity measure component is the geometric mean of two
#: horizontal components
DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.AVERAGE_HORIZONTAL
#: Supported standard deviation types are inter-event, intra-event
#: and total
DEFINED_FOR_STANDARD_DEVIATION_TYPES = {
const.StdDev.TOTAL, const.StdDev.INTER_EVENT, const.StdDev.INTRA_EVENT}
#: Required site parameter is only Vs30
REQUIRES_SITES_PARAMETERS = {'vs30'}
#: Required rupture parameters are magnitude only (eq. 1).
REQUIRES_RUPTURE_PARAMETERS = {'mag'}
#: Required distance measure is Rjb (eq. 1).
REQUIRES_DISTANCES = {'rjb'}
kind = "base"
[docs] def compute(self, ctx, imts, mean, sig, tau, phi):
"""
See :meth:`superclass method
<.base.GroundShakingIntensityModel.compute>`
for spec of input and result values.
"""
for m, imt in enumerate(imts):
C = self.COEFFS[imt]
mean[m] = (_get_magnitude_term(C, ctx.mag) +
_get_distance_term(self.kind, C, ctx.rjb, ctx.mag) +
_get_site_term(self.kind, C, ctx.vs30))
# Units of GMPE are in terms of m/s (corrected in an Erratum)
# Convert to g
if imt.string.startswith(('PGA', 'SA')):
mean[m] = np.log(np.exp(mean[m]) / g)
else:
# For PGV convert from m/s to cm/s/s
mean[m] = np.log(np.exp(mean[m]) * 100.)
# Get standard deviations
sig[m] = C['sigma']
tau[m] = C['tau']
phi[m] = np.sqrt(C['phi0'] ** 2. + C["phiS2S"] ** 2.)
COEFFS = CoeffsTable(sa_damping=5, table=open(KOTHA_CSV).read())
[docs]class KothaEtAl2016Italy(KothaEtAl2016):
"""
Regional varient of the Kotha et al. (2016) GMPE for the Italy case
"""
kind = "ITA"
[docs]class KothaEtAl2016Turkey(KothaEtAl2016):
"""
Regional varient of the Kotha et al. (2016) GMPE for the Turkey case
"""
kind = "TUR"
[docs]class KothaEtAl2016Other(KothaEtAl2016):
"""
Regional varient of the Kotha et al. (2016) GMPE for the "Other" case
"""
kind = "other"