Satellite-based discharge assimilation into global water resources model

Abstract

The incorporation of observed hydrological information reduces the uncertainties in simulations of water resource systems, yet it is challenging due to the limited availability of in-situ observations. In this study, we have developed a globally applicable data assimilation scheme that integrates the satellite-based discharge (RSQ) into the global water resources model H08 was developed. The RSQ-assimilated discharge was validated at 66 gauging stations in the Missouri River basin, and it showed an considerable improvements in NSE and NRMSE compared to the case without assimilation. The observing system simulation experiment was conducted to analyze how the assimilation of RSQ changed unobservable hydrological components. The result shows that the pseudo-RSQ can successfully constrain the modeled river storage, but further assimilation of observational data and updates of other hydrological quantities are required to achieve a more realistic terrestrial water balance.