def get_source_term_div(heat_fluxes, metric):
    """
    Compute the radiative in the conventional way by taking the divergence of
    the radiative heat flux vector

    Parameters
    ----------
    heat_fluxes: numpy arrays containing heat fluxes in x, y, and projected
    onto the boundaries
    metric: object containing information relative to metric (gradients,
    coordinates, etc.)

    Returns
    source_term: radiative source term
    -------

    """
    q_x = heat_fluxes[0]
    q_y = heat_fluxes[1]
    grad_x = metric.grad_x_csr
    grad_y = metric.grad_y_csr
    radiative_source_term_div = grad_x.dot(q_x) + grad_y.dot(q_y)
    return radiative_source_term_div
