Author manuscript, published in "GGP Workshop, Jena: Germany (2006)" Inclinometry and geodesy: an hydrological perspective

Two orthogonal, precise and low drift tiltmeters have been installed in the Vosges mountains in order to study environmental surface loading. The first results show the great sensitivity (10−10 radians), stability (negligible drift) of the instrument, and its ability to be used as a tool to study hydrological loading. This work focuses on local and regional hydrological physical modelling, with a stepwise refinement of mass balance calculations on a geodetic purpose. We show that meteorological forcing mainly drives stock variations inside a hydrological unit, it is therefore necessary to take great care of precipitation and evapotranspiration. Uncertainty assessment on stock variations is also raised, and shows that hydrological models bring good estimation of short term water stock variations, but that long term geodetic variations provide complementary information for stored water modelling.