INTERGEO Agenda - english

How well can hydrological models capture changes in Earth’s water storage in data-scarce regions such as the Congo River Basin? In this presentation, Terrestrial Water Storage (TWS) dynamics and their individual storage compartments (i.e., soil moisture, groundwater, water in lakes, rivers, and reservoirs) are explored using outputs from OS LISFLOOD, an open-source spatially distributed water resources model developed by the Joint Research Centre of the European Commission. Simulations forced with ERA5 atmospheric reanalysis data are evaluated against GRACE satellite gravimetry observations and compared with simulations driven by alternative meteorological forcing datasets as well as other hydrological models. The evaluation focuses on different temporal TWS signal components and is performed using statistical measures such as correlation, Root Mean Squared Differences, and Kling-Gupta Efficiency. Special attention is given to the low performance of OS LISFLOOD in the Congo Basin in the low-frequency parts of the signal when forced with ERA5 data. By analyzing differences between meteorological forcing datasets, model sensitivity to different atmospheric forcings, and the influence of calibration, this study aims to identify potential sources of uncertainty in large-scale hydrological simulations.