Changes in settlement patterns are often argued to reflect climatic change, which may make certain areas more or less hospitable depending on the adaptability of subsistence practices. This study models the impact of El Niño-Southern Oscillation (ENSO) events on phases of occupation and abandonment over the past 4500 years at Pashimbi in the Ecuadorian Amazon. While earlier occupations and abandonments seem to correlate with climatic events, associations post-3000 BP are less clear, potentially indicating that populations adapted to wetter conditions and, the authors argue, that the El Niño-Southern Oscillation was not the main determinant in the decision to abandon settlements.

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 examines the impact of El Niño events on human occupation and abandonment in the Ecuadorian Amazon over the last 4,500 years BP, focusing on the Pashimbi site. Seventeen calibrated radiocarbon dates and probability density functions were used to define settlement periods. Climatic influence was evaluated through principal component analysis (PCA) applied to X-ray fluorescence (XRF) data from a core taken from Lake Llaviucu, where the first component explained 98.42 % of the variance. Wavelet analysis revealed periodicities of 2-8 years, consistent with ENSO. Results indicate that the earliest Pashimbi settlements (ca. 4089 BP) were associated with El Niño phases, whereas those after 3000 BP showed no correlation. Although two patterns were observed, Bartlett’s test (p = 0.9026) demonstrates that there are no significant differences between ENSO impacts during occupation and abandonment periods.

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.