Integration of Remote Sensing and Photogrammetry as a Solution for Studying Shoreline Change in NW Spitsbergen, Svalbard

It is estimated that just over a third of all shorelines in the world are located within polar regions, yet only a small percentage of them has been subject to research and monitoring so far. This extremely important component of the environment is constantly being transformed in times of climate change. With the help of remote sensing and automatic processing models, using generally available satellite programmes, it is becoming possible to conduct morphometric analyses, including in a long-term framework. The article presents the results of 40-year monitoring of changes in the shoreline of Northwest Spitsbergen, divided into sub-periods. From thousands of candidate scenes acquired by Landsat 5–8 and Sentinel-2 and processed using semi-automated tools, only 129 images (1.2% of the initial dataset) met the strict inclusion criteria of spatial congruence with AOI zones and comparable acquisition conditions, namely similar sea levels and cloud cover. Five zones, all located on sandy beaches, were selected for the analysis to demonstrate the main directions of changes and transformation of the Arctic coastlines. The zones had a total length of over 37 km and were chosen owing to their potential differences in oceanic qualities (as verified), spatial conditions (location inside and outside Forlandsundet), and geomorphological considerations. The beaches were predominantly stable and accumulative, with the area changing from ˗0.02 ± 0.09 m yr­1 up to 0.96 ± 0.14 m yr­1 (in the long-term perspective, from ~ 1990 until 2024). It must be emphasised that a comparative analysis of satellite images was carried out with a short-term perspective to follow changes in the river mouth and the emergence and transformation of new lakes, spits, and bays. The results for the selected zones were rigorously validated through comparison with high-resolution DEMs and orthomosaics generated from UAV surveys carried out between 2021 and 2023.