article · Journal of Hydrology Regional Studies
Researchers have developed an improved 40-year daily hydrological reanalysis of the Congo River basin covering the period from 1981 to 2020. The work integrates a large-scale hydrologic-hydrodynamic model with lake storage dynamics and applies data assimilation using both in-situ measurements and remote sensing observations. Incorporating lake dynamics substantially improves model correlation, while data assimilation reduces river discharge errors by approximately 13 percent. The reanalysis examines severe floods and droughts alongside their teleconnections to the El Niño-Southern Oscillation. The findings reveal that the severe southern and central flood of 1997 to 1998 was statistically linked to a major El Niño, unlike the 2019 to 2020 flood. Furthermore, major droughts in 1983 to 1984 and 2011 to 2012 strongly correlate with prior El Niño and La Niña events, showing a delay of roughly 10 to 12 months.
The Congo River basin is the second largest globally, where severe floods and droughts heavily affect ecosystems and local communities. By better simulating daily river flows and establishing time-lagged links between extreme weather and global climate drivers like El Niño, this research provides clearer insight into water variability across vast tropical river systems.
The reanalysis model and data assimilation framework could be used by environmental agencies, river basin managers, and hydrological forecasting bodies to monitor water resources and assess climate risks. The work represents applied research tested across historical datasets, offering a baseline methodology for larger-scale regional monitoring, though the abstract does not indicate immediate commercial software deployment.
AI-generated from the published abstract. Always read the original work before citing.
The Congo River basin (CRB), the world's second-largest river system, is subject to extreme hydrological events that strongly impact its ecosystems and population. Here we present an improved 40-year (1981–2020) hydrological reanalysis of daily CRB discharge and analyze the spatiotemporal dynamics of recent major CRB floods and droughts, and their teleconnection with El Niño-Southern Oscillation (ENSO), the dominant driver of tropical precipitation. We employ a large-scale hydrologic-hydrodynamic model (MGB) with lake storage dynamics representation and a data assimilation (DA) technique using in-situ and remote sensing observations. The MGB model demonstrates satisfactory performance, with Kling-Gupta efficiency metric of 0.84 and 0.71 for calibration and validation, respectively. Incorporating lake representation substantially enhances simulations, increasing the Pearson correlation coefficient from 0.3 to 0.63. Additionally, DA yields a ∼13% reduction in discharge errors via cross-validation. We find that the 1997–1998 flood impacting the south and central CRB is statistically linked to a major El Niño event during that period. However, no such association is found for the 2019–2020 flood. Severe droughts in 1983–1984 and 2011–2012, affecting northern and southern CRB respectively, exhibit strong correlation with preceding El Niño and La Niña events, with a ∼10–12 months lag. This study advances understanding of the intricate interplay between spatiotemporal hydrological variability in CRB and large-scale climate phenomena like ENSO.
This page summarises published work. The authoritative version sits with the publisher.
DOI: 10.1016/j.ejrh.2023.101563
Is something wrong with this record? Report it or request removal.
Discussion
Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.
No discussion yet. Open the first thread.
New to MARATTO™? Create a free account.
