High-Andean wetlands are critical ecosystems for water regulation and carbon storage. This study analyzes the impact of climate variability on vegetation dynamics in eight wetlands located in the Estero Ortiga sub-basin, within the Los Nogales Nature Sanctuary (Metropolitan Region, Chile), between 2017 and 2024. We used time series of NDVI and NDCI indices derived from Sentinel-2 imagery (January 2017 to September 2024), along with monthly temperature and precipitation data from ERA5-Land (January 2016 to September 2024). Trends were assessed through linear regression, and vegetation–climate relationships were analyzed using Pearson correlations with a one-year lag. Results show a progressive decline in vegetation cover (slope: −2.04 × 10⁻⁵ NDVI) and chlorophyll content (slope: −1.15 × 10⁻⁵ NDCI), with strong positive correlations between annual precipitation and vegetation indices in the subsequent summer (R = 0.83–0.88 for NDVI; R = 0.84–0.90 for NDCI). Annual NDVI reclassification highlighted a reduction in healthy vegetation cover from 2020 onward. This research provides novel evidence linking climate trends and vegetation health in high-Andean wetlands, reinforcing the utility of satellite-based indicators for conservation monitoring.

In the mountainous and foothill areas of Santiago, Chile, debris flows and debris floods have been recurrent over recent decades, triggered by short-duration, high-intensity summer rainfall events. These events have caused significant damage to infrastructure and have affected the population, including loss of human lives. This study assesses the susceptibility to debris flow and debris flood generation in the Arrayán and Gualtatas stream basins, located in the Metropolitan Region, using satellite and cartographic data. A Susceptibility Index (SI) was determined through the analysis of 14 conditioning factors, grouped into three main categories: geology, geomorphology, and soil conditions. The weighting and ranking of each factor’s importance were carried out using the Analytic Hierarchy Process (AHP). The results, presented in a susceptibility map, indicate that 60.78% of the study area exhibits low to very low susceptibility, 24.64% moderate susceptibility, and 14.58% high to very high susceptibility, concentrated in stream headwaters, steep slopes, and areas with unconsolidated deposits. Recent debris flow events that have reached urban areas coincide with high-susceptibility zones, validating the methodology and cartographic products, which can support land-use planning and risk management efforts.

Difficult access and a lack of in situ data limit monitoring of high-Andean wetlands, which are key components of water regulation in central Chile. This study analyzes the multitemporal dynamics of vegetation in three high Andean wetlands of the headwater (1HW), lateral (2LW), and confluence (3CW) types in the Los Nogales Nature Sanctuary between 2018 and 2025. We integrated Sentinel-2 Level 2A images, annual accumulated precipitation from the ERA5-Land product (lag-1 year), and high-resolution UAV-derived boundaries to characterize six spectral indices (NDVI, EVI, NDRE704, NDRE705, NDWI, and SAVI) and their relationship with water variability. Annual precipitation ranged from ~420 to 780 mm during a regional megadrought. The headwater wetland showed the greatest climate sensitivity, with significant correlations between the previous year's precipitation and NDVI, NDRE705, EVI, SAVI, and NDWI (|R| ≥ 0.70; p < 0.05), while in the lateral and confluence wetlands, the relationships were moderate or weak. Multitemporal mosaics showed maximum vegetative vigor between 2018 and 2021, followed by a decline. Overall, the results confirm that integrating the Sentinel-2 series, climate reanalysis, and UAV delimitation is an effective tool for ecohydrological monitoring and management of high-Andean wetlands.