code: def _beta(catchment):
          
          lnbeta = -1.1221 \
                   - 0.0816 * log(catchment.descriptors.dtm_area) \
                   - 0.4580 * log(catchment.descriptors.saar / 1000) \
                   + 0.1065 * log(catchment.descriptors.bfihost)
          return exp(lnbeta)
docs: Return beta, the GLO scale parameter divided by loc parameter estimated using simple regression model
  
          Methodology source: Kjeldsen & Jones, 2009, table 2
  
          :param catchment: Catchment to estimate beta for
          :type catchment: :class:`Catchment`
          :return: beta
          :rtype: float