论我国高程基准面问题

On the Problem of National Datum Levels in China

The history and problems of old datum levels have been analysed in this paper. Contradictions and errors in base level observation technology, tidal level calculation and the published table of datum level relation between the old base levels and the " 56 yellew sea level system" are pointed out. The influences of the short tidal data and the " higher sea level in the south and lower sea level in the north" are expounded. At the end, some ideas and suggestions are put forward for the new level system " 85 National Datum Level".