def pressure_fao(z=1331):
    """
    Calculate the pressure for a certain elevation if no measurements are available.
    FAO 1998

    Args:

    Returns:
        p (float) : atmospheric pressure [hPa]

    """

    p = 101.3 * ((293 - 0.0065 * z) / 293.) ** 5.26

    return p * 1e1