Project by Max Warnock
Team members: Luca Hadley & PJ Bovaconti
Mountain snowpack and glaciers are an important freshwater source for agriculture and developed areas that are downstream (Lindsey, 2024). Specifically the alpine region of Saas Fee, Switzerland has large snowfields and several large glaciers including the Allalin glacier that share a watershed with large agricultural regions, and contain large cities such as Milan, Italy (Bolinger). The human reliance on these water resources is significant. Therefore, assessing the stability of these resources is important for determining how much water will be available in the future, and for understanding the consequences of climate change. This research uses remotely sensed imagery to identify these changes. Using the United States Geological Survey's Earth Explorer, images of the region from September of 2013 and 2024 were downloaded from Landsat 8 and 9, respectively (USGS, 2024). Several processes were then implemented to assess change. Firstly, a band combination of 5, 4, 2 (RGB), was used to clearly visualize snow and ice in contrast with the surrounding land cover. Supervised land cover classifications were then performed using Google Earth Engine (GEE). From this, binary rasters of each image were created to show areas of snow and ice versus land cover without snow/ice. The 2024 raster was subtracted from the 2013 raster which created a change detection map showing areas that changed due to differences in snowpack. Finally, to assess how these areas changed, the Normalized Difference Snow Index (NDSI) was applied to the images (NV5). A difference image was calculated from the two NDSI images to identify areas where snowpack increased or decreased over the study period. The results of this analysis showed that the extent (edges) of the snowpack of the region generally decreased over the study period. Areas where the most melting was identified are at lower elevation where temperatures are warmer and more susceptible to melting. These results are expected due to the general warming atmospheric conditions due to human caused climate change (Blunden, 2020).
Allalin Glacier in 2015, Switzlerland, viewed from below.
Image credit: PJ Bovaconti