Small Arctic coastal catchments and coastal lagoon systems are some of the most vulnerable to climate change. Glacial retreat and the development of glacial lakes and drainage systems provide opportunities for hazardous events such as GLOFs. We observe that the stability of lagoons and their associated barriers are controlled by the frequency and magnitude of storms approaching the coasts, access to sediment supplies and resilience to sea-level rise. Based on multidecadal remote sensing data, we were able to identify the rate of glacial recession, the development of glacial lakes, vegetation response to climate change and a GLOF event, and shoreline and lagoon responses to the environmental shifts within the small catchment. Here we present an example of lagoon system evolution where a glacial outburst flood exerted significant control over lagoon drainage and coastal barrier stability.

Small Arctic catchments that are sensitive to climate change reinforced by Arctic amplification remain poorly studied. Since the end of the Little Ice Age (LIA) glaciers on Svalbard have been retreating, and thus, many catchments have transformed from glaciated or partly glaciated to ice-free conditions. Our study focuses on changes that have occurred since the end of the LIA in a small High Arctic mountain catchment, Bratteggdalen. In this study, we traced changes in the Bratteggbreen glacier areal extent since 1976 with parallel vegetation analysis using Landsat and Sentinel data. The geomorphology of Bratteggdalen was mapped and basic morphometric analyses, such as long profile, hypsometric curve, slope and aspect orientation analyses were carried out. We also present a map of landforms in Bratteggdalen based on a fieldwork in 2018 and an analysis of orthophotomaps. Through this research, we enhance the knowledge of small catchments in polar regions.

The development of remote sensing instruments and methods has revolutionised work practices worldwide, resulting in a new field of research. Remote sensing has significantly expanded the possibilities for detailed research, spanning from biological to urban studies, by constantly imaging the Earth. Numerous photogrammetric campaigns and satellite missions have been increasing the possibilities for conducting research that includes larger areas and time scales while minimising the need for fieldwork. This is particularly useful in polar regions, where fieldwork is complicated by harsh weather conditions, hard-to-reach research areas, polar nights, and the need for high funding and logistical support. Here available algorithms that help to track environmental shifts in the small Arctic catchments, such as changes in ice, snow, vegetation, and water are presented.

Climate change influences worldwide freshwaters with the most prominent effects in the Arctic and Alpine regions. Environmental management in proglacial zones underlain by permafrost requires understanding of hydrological regimes and water retention patterns. However, there is limited long-term data on the catchment-scale freshwater flow and retention for ecosystems within the continuous permafrost zones. Here, we characterized the hydrometeorological controls on the glacial-fluvio-lacustrine regime in a model Arctic catchment (SW Svalbard) to inform contingency plans for regions endangered by glacial-floods and permafrost landslides. We compiled a comprehensive hydro-meteorological dataset between 2005 and 2019 from a larger database (1972-2019) and applied bootstrapping, random forest, and multiple regressions, to elucidate the relationships between drivers (temperatures, sunshine duration, precipitation) and the intensity of freshwater flows. The hydrology exhibits strong seasonality with a pronounced peak between June and July controlled by precipitation (R = 0.56). From August to September, low-to-intermediate freshwater discharge is controlled by interactive effects of air temperatures and precipitation (R = 0.71). The interaction between hydrometeorology and catchment-scale discharge is stronger for August and September compared to June and July. The strongest warming trend between August and September (1979-2019) makes this period particularly relevant with regards to the long-term changes and environmental management in the permafrost-underlain catchments. Indeed, our northern hemisphere meta-analysis (n = 1975) revealed that majority of glacial floods (51 %) occurs at that time. We argue that permafrost management should include monitoring of surface temperature, precipitation and snow cover enabling establishment of stabilizing infrastructure in sensitive regions whenever threshold values are exceeded (i.e., Tmin >4 °C; P > 30 mm) and discharges increase.