In the global water cycle, terrestrial water storage is the link between atmosphere and ocean. Global changes in terrestrial water storage can be observed by satellite-based gravity measurements. Terrestrial water storage variations are also largely responsible for Earth rotation variations on seasonal time scales.

The Land Surface Discharge Model (LSDM) simulates globally the vertical and lateral water transport and storage on land surfaces. Physics and parametrization are based on the Hydrological Discharge Model (HDM) and the Simplified Land Surface Scheme (SLS; Hagemann und Dümenil, 1998, 2003). Forced by precipitation, evaporation and temperature the hydrological model LSDM captures the most important continental water mass transport processes and storage compartements (soil moisture, snow, rivers and lakes, runoff, drainage).

The separation of individual storage compartements by the LSDM model is necessary to analyze and interpret the integral observables from gravity missions and Earth rotation observations.

• Dill, R. (2008): Hydrological model LSDM for operational Earth rotation and gravity field variations. GFZ ScientificTechnical Report STR08/09.
• Dill, R. (2009): Hydrological induced Earth rotation variations from stand-alone and dynamically coupled simulations.  In: Soffel, M.; Capitaine, N. (Eds.), Proceedings of the Journées 2008 Systèmes de Référence Spatio-temporels & X. Lohrmann-Kolloquium : 22-24 September 2008 - Dresden, Germany, 115-118.
• Hagemann, S., Dümenil, L. (1998): Documentation for the Hydrological Discharge Model, Technical Report No. 17. Max Planck Institute for Meteorology, Hamburg, Germany, 42pp.
• Hagemann, S., Dümenil Gates, L. (2003): Improving a subgrid runoff parameterization scheme for climate models by the use of high resolution data derived from satellite observations. Clim. Dyn. 21, 349-359.
• Walter, C. (2008): Simulation hydrologischer Massenvariationen und deren Einfluss auf die Erdrotation, Ph.D.-thesis, 195pp., TU Dresden, Germany.

• OMCT-Model