Using Water Storage Variations Derived from GRACE to Calibrate a Global Hydrology Model
Werth, S1; GŁntner, A.1; Petrovic, S.2; Schmidt, R.2; Kusche, J.2
1GeoForschungsZentrum Potsdam, Section Engineering Hydrology; 2GeoForschungsZentrum Potsdam, Section Gravity field and Gravimetry

Spatio-temporal variations of the Earth's gravity field derived from monthly time series of US-German satellite gravity mission GRACE trace ongoing mass redistributions on, at and below the Earth's surface. These are induced by various processes. In particular gravity variations due to continental hydrology can be observed. Vice versa, after transforming the gravity variations into maps of surface mass anomalies, such data shall be used for the quantification of large-scale mass transfers within the global water cycle. Therefore, GRACE provides a comprehensive data set for the validation and calibration of large-scale hydrological models. In this contribution, we present the current status on the calibration of the WaterGAP Global Hydrology Model (WGHM) based on surface mass variations derived from the current RL04 GRACE-only gravity field model time series generated at GFZ Potsdam (GFZ-RL04). WGHM simulates the continental water storage of the components interception, soil, snow, groundwater and surface water. In its original version WGHM is calibrated against observed river runoff at 1235 discharge stations world wide. Combining both the present station-based accuracy of the model in terms of river discharge and the integrative nature of the GRACE data with global coverage, more improved simulation results are expected from a multi-objective calibration approach. We emphasize the innovative contribution of the GRACE satellite mission to the field of hydrological modelling.


Legal Disclaimer - Glossary - FAQ - Site Map - Contact us Last updated: 09-Feb-2010