Evaluating catchment-scale hydrological modeling by means of terrestrial gravity observations

Shaakeel Hasan, Peter A. Troch, Patrick W. Bogaart, Corinna Kroner

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

In a previous study (Hasan et al., 2006) we applied time series analysis and distributed hydrological modeling techniques to investigate the effect of hydrological processes on observed terrestrial gravity residuals. In this study we apply terrestrial gravity observations (measured in one location) to constrain simple hydrological models in a catchment around the gravimeter. A superconducting gravimeter observes with high frequency (1 Hz) the temporal variations in the gravity field with high accuracy (sub nm s-2 for hourly variation) near Moxa, Germany since 1999. Hourly gravity residuals are derived by filtering and reducing for Earth tides, polar motion, barometric pressure variations, and instrumental drift. These gravity residuals show significant response to hydrological processes (precipitation, evaporation, surface and subsurface flow) in the catchment surrounding the observatory. We can thus consider the observed gravity change as an integrator of catchment-scale hydrological response (similar in nature as discharge measurements), and therefore use it to constrain catchment-scale hydrologic models. We test a set of simple water balance models against measured discharge, and employ observed gravity residuals to evaluate model parameters. Results indicate that a lumped water balance model for unsaturated storage and fluxes, coupled with a semidistributed hydraulic groundwater model for saturated storage and fluxes, successfully reproduces both gravity and discharge dynamics.

Original languageEnglish (US)
Article numberW08416
JournalWater Resources Research
Volume44
Issue number8
DOIs
StatePublished - Aug 2008

ASJC Scopus subject areas

  • Water Science and Technology

Fingerprint Dive into the research topics of 'Evaluating catchment-scale hydrological modeling by means of terrestrial gravity observations'. Together they form a unique fingerprint.

Cite this