From DIY sensors to satellites: a cost-effective approach to monitor morphohydrodynamics at the Ebro River mouth

River mouths are highly dynamic environments that are increasingly impacted by anthropogenic pressures such as upstream damming, and climate-driven changes in discharge and wave regimes. However, long-term, high-resolution monitoring of these sensitive systems is often limited by the cost and spatial coverage of conventional observing technologies. Here, we present an integrated and cost-effective monitoring strategy that combines do-it-yourself (DIY) instrumentation with satellite observations to improve spatio-temporal coverage of coastal processes.

From 2023 to 2025, six bathymetric campaigns were carried out at the Ebro River mouth (NW Mediterranean Sea). These campaigns included bathymetry surveys, the deployment of Lagrangian buoys and CTD measurements. They aimed to investigate the influence of river discharge regimes on the dynamics of this wave-dominated delta, as well as to improve the understanding of sediment transport processes at the river mouth.

Analysis of the campaigns combined with spaceborne observations shows that, during periods of low-discharge, sediment accumulates in front of the river mouth, leading to the emergence of the mouth bar. Additionally, increased wave activity from the southeast increases longshore sediment transport northward. Consequently, waves erode sediment from the southern hemidelta and deposited in front of the river, promoting the closure of the main channel and the formation of a new discharge channel toward the south. These morphodynamic changes directly affect delta stability, habitat distribution and ecosystem functioning, with implications for coastal management and conservation under increasing human pressure.

Keywords: coastal morphology; delta dynamics; anthropogenic pressure; low-cost monitoring; DIY; 

This work has been funded by EBRO-CLIM research project PID2024-155310OB-I00 financed by MICIU/AEI/10.13039/501100011033/FEDER, UE.