Flash-Flood-Induced Changes in the Hydrochemistry of the Albufera of Valencia Coastal Lagoon

In the context of climate change, extreme meteorological events such as severe storms produced by an isolated high-level atmospheric depression (known in Spanish as “Depresión Aislada en Niveles Altos”—DANA) are becoming increasingly frequent in the Mediterranean region, posing significant risks to ecosystems and human infrastructure. This study evaluates the impact of a DANA event in October 2024 on the water quality of Albufera Lake (Spain), a crucial Mediterranean wetland. A comprehensive evaluation was conducted by combining field data on physicochemical and biological parameters with satellite observations (Sentinel-2 and Landsat-8) to assess alterations before and after the event. Variables such as conductivity, nitrate, and total solids exhibited significant reductions immediately following the DANA, with conductivity decreasing by 82% compared to pre-event levels. These alterations signify a substantial renewal of the lake system driven by heavy rainfall and subsequent water releases. However, the lake demonstrated signs of recovery toward pre-event conditions over the following month. These results are consistent with previous findings, underscoring the system’s resilience and the necessity of periodic water releases to maintain ecological balance. The use of remote sensing tools effectively captured these dynamics, offering valuable insights for the long-term monitoring of water quality. This study highlights the urgent need for proactive management strategies to mitigate the effects of increasingly intense meteorological disturbances.