Abstract We used Sentinel-2 imagery time series to generate a vegetation map for the Northern part of the Antarctica Peninsula and offshore islands, including the South Shetlands. The vegetation cover was identified in the NDVI maximum value composite image. The NDVI values were associated with the occurrence of algae (0.15 – 0.20), lichens (0.20 – 0.50), and mosses (0.50 – 0.80). The vegetation cover distribution map was validated using the literature information. Generating a vegetation map distribution on an annual basis was not possible due to high cloud cover in the Antarctic region, especially in coastal áreas, so optical images from 2016 to 2021 were necessary to map the vegetation distribution in the entire study área. The final map analyzed in association with the weather data shows the occurrence of a microenvironment over the western islands of the Antarctic Peninsula that provided vegetation growth conditions. The Sentinel-2 images with 10m spatial resolution allow the assembly of accurate vegetation distribution maps for the Antarctica Peninsula and Islands, the Google Earth Engine cloud computing being essential to process a large amount of the satellite images necessary for processing these maps.

Abstract The remote sensing techniques must be used to obtain long-term information in remote areas, like the Antarctic continent, to monitor the environmental productivity and its changes. The aim of this work was to analyze the surface reflectance profile patterns for the Antarctic biological soil crusts (algae, lichens, and mosses) in an area of Nelson Island (South Shetland Islands, maritime Antarctic), calculated from Landsat and Sentinel-2 images to identify its similarities and differences due to targets, sensors and acquired date. The surface reflectance values for Antarctic biological soil crusts are similar for those observed for biological soil crusts in other Earth extreme environments, like deserts. In Landsat images, the differences among biological soil crusts surface reflectance were identified at visible and near-infrared wavelengths and for Sentinel-2 images, the differences occur at visible, red-edge and shortwave infrared wavelengths, showing the feasibility of using surface reflectance products to identify these different crusts, despite its inherent pixel spectral mixture. Long-term biophysical parameters from such crusts as retrieved from orbital data is not possible due to very low cloud-free images over the Antarctic, which prevents building a consistent surface reflectance time-series which covers all biological soil crusts growth season.

Abstract Climate change and glacial disasters directly affect the Andean periglacial populations in the environmental, social, economic and cultural spheres. Regional atmospheric warming is causing an increasing retreat of glaciers in the Cordillera Blanca, Peru. The melting of these glaciers causes, among other consequences, the formation of new glacial lagoons and an increase in volume of the pre-existing lagoons; both phenomena increase the possibility of glacial disasters. Thus, this paper reports an investigation of perceptions and adaptations to climatic change and glacial disasters in the Cordillera Blanca, Department of Ancash, Peru, through the ethnographic method with the campesino communities of Vicos and Humacchuco; this method included observations and semi-structured interviews with managers and campesinos. The measures adopted by the managers are, predominantly, engineering to reduce disasters, such as increasing of dike sizes and lagoon drainages. The retreat of the glaciers, as noted by the campesino communities themselves, is the main perception of the impacts of climate change. We suggest that the choice of safe places to live in campesino communities is the main strategy of adaptation and is related to an ancestral ethnoknowledge. The reterritorialization of sites susceptible to glacial disasters is not only due to the need to have a place (to plant, to live), but is also due to the topophilic feelings formed by the affective link between a person and a place. There is a central and structural issue that adds to these problems: the development model prevailing in Peruvian postcolonial society tends to complicate possible strategies for adapting to climate change in the Andes.

Resumo As mudanças climáticas e os desastres glaciais afetam diretamente as populações periglaciais andinas nas esferas ambientais, sociais, econômicas e culturais. O aquecimento atmosférico regional está provocando a crescente retração das geleiras na Cordilheira Branca (Peru) ao longo das últimas décadas. O derretimento dessas geleiras implica, entre outras consequências, na formação de lagoas glaciais e o acréscimo do volume daquelas pré-existentes, o que aumenta a possibilidade de desastres glaciais. Assim, este trabalho relata investigações sobre percepções e adaptações às mudanças climáticas e aos desastres glaciais na Cordilheira Branca, Departamento de Ancash, Peru, por meio do método etnográfico junto às comunidades campesinas de Vicos e Humacchuco, incluindo a observação direta e entrevistas semiestruturadas com gestores e campesinos. As medidas adotadas pelos gestores são, predominantemente, obras de engenharia para reduzir os desastres, como o aumento dos diques e do desague das lagoas. A retração das geleiras, como apontada pelas próprias comunidades campesinas, é a principal percepção dos impactos das mudanças climáticas. Sugerimos que a escolha de locais seguros para habitar pelas comunidades campesinas é a principal estratégia de adaptação e é relacionada à um etnoconhecimento ancestral. A reterritorialização dos locais suscetíveis aos desastres glaciais se dá pela necessidade de se ter um lugar (para plantar, para viver), mas também devido aos sentimentos topofílicos pelo elo afetivo entre a pessoa e o lugar. Há uma questão central, estrutural e estruturante, que se soma a esses problemas: o modelo de desenvolvimento vigente na sociedade pós-colonial peruana tende a complexificar possíveis estratégias de adaptação às mudanças climáticas nos Andes.