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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _beta(catchment):
 """ 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 """

        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)