Articles | Volume 14, issue 9
Hydrol. Earth Syst. Sci., 14, 1715–1730, 2010
https://doi.org/10.5194/hess-14-1715-2010

Special issue: Observing and modeling the catchment-scale water cycle

Hydrol. Earth Syst. Sci., 14, 1715–1730, 2010
https://doi.org/10.5194/hess-14-1715-2010

  01 Sep 2010

01 Sep 2010

The benefits of gravimeter observations for modelling water storage changes at the field scale

B. Creutzfeldt, A. Güntner, S. Vorogushyn, and B. Merz B. Creutzfeldt et al.
  • Deutsches GeoForschungsZentrum GFZ, Section Hydrology, Potsdam, Germany

Abstract. Water storage is the fundamental state variable of hydrological systems. However, comprehensive data on total water storage changes (WSC) are practically inaccessible by hydrological measurement techniques at the field or catchment scale, and hydrological models are highly uncertain in representing the storage term due to the lack of adequate validation or calibration data. In this study, we assess the benefit of temporal gravimeter measurements for modelling WSC at the field scale. A simple conceptual hydrological model is calibrated and evaluated against records of a superconducting gravimeter (SG), soil moisture, and groundwater time series. The model is validated against independently estimated WSC based on lysimeter measurements. Using gravimeter data as a calibration constraint improves the model results substantially in terms of predictive capability and variation of the behavioural model runs. Thanks to their capacity to integrate over different storage components and a larger area, gravimeters provide information on total WSC that can be used to constrain the overall status of the hydrological system in a model. The general problem of specifying the internal model structure or individual parameter sets can, however, not be solved with gravimeters alone.