Proposed hydropower dams at more than 350 sites throughout the Amazon require strategic evaluation of trade-offs between the numerous ecosystem services provided by Earth’s largest and most biodiverse river basin. These services are spatially variable, hence collective impacts of newly built dams depend strongly on their configuration. We use multiobjective optimization to identify portfolios of sites that simultaneously minimize impacts on river flow, river connectivity, sediment transport, fish diversity, and greenhouse gas emissions while achieving energy production goals. We find that uncoordinated, dam-by-dam hydropower expansion has resulted in forgone ecosystem service benefits. Minimizing further damage from hydropower development requires considering diverse environmental impacts across the entire basin, as well as cooperation among Amazonian nations. Our findings offer a transferable model for the evaluation of hydropower expansion in transboundary basins.

The El Niño–Southern Oscillation (ENSO) has been a key modulator of climate variability in Ecuador, generating differentiated impacts across regions and influencing both ecosystems and human societies. The objective of this study was to analyze the ENSO signal through wavelet transforms applied to historical precipitation series from 17 conventional meteorological stations between 1964 and 2020, in order to identify high- and low-frequency oscillations. These signals were related to records of extreme events reported across the four regions of Ecuador. The results showed that 2–8-year oscillations coincided with the main flood and drought episodes, whereas multidecadal signals reflected persistent patterns. In conclusion, ENSO exerted a sustained influence on the occurrence of extreme hydrometeorological events, highlighting the vulnerability of human settlements during the Anthropocene.

This study documents the presence and evolution of the 2023-2024 El Niño event in Ecuador’s insular region based on precipitation data from meteorological stations M0221 (San Cristóbal - Galápagos), M0191 (Baltra), and M1236 (San Cristóbal - Airport), all operated by INAMHI. Conventional and automatic observations are integrated with spectral analysis using the wavelet transform and historical series dating back to 1964. The results show anomalous rainfall behavior at all stations, with monthly totals significantly exceeding the normal climatology (1981-2010) during the first quarter of 2024, reaching maxima of 282 mm in February and 267.7 mm in March. From May onward, a transition toward drier conditions is observed, coinciding with the weakening of the ENSO signal. Spectral analysis reveals a significant signal in the 2-8-year band, consistent with variability associated with ENSO. This work contributes to the regional characterization of ENSO in the eastern Pacific and underscores the importance of strengthening climate monitoring in the Galápagos, a strategic yet sparsely studied region due to its isolated geographic setting on the Equator. The findings are relevant for improving understanding of ENSO impacts in South America and for bolstering early warning systems in sensitive areas of the South Pacific.