Assessment and Modelling of Coastal Erosion Processes in Hiorthhamn, Longyearbyen (Svalbard).

Coastal Erosion in Arctic is an ongoing phenomena which represents a relevant engineering topic for its social and environmental implications. It is the result of several processes that highly depend on the local settings that characterize the shoreline. Foremost, the climate conditions and the materials composition. Modelling tools are widely used to represent such phenomena, with the purpose of giving an estimation of shoreline recession and therefore provides a future projection, useful for the engineering practise. The objective of the study is to estimate present and future recession of an Arctic coastline located in the Archipelago of Svalbard. This is done in connection with the preservation of an historical and cultural remain located in the Hiorthhman shoreline: the "Taubanestasjonen" (cable station). Here it is shown that the erosion rate measured in the past is underestimated and that the future of the shoreline highly depends on future climate scenarios. The erosion rate measured from 2011 to 2022 was found to be 2.15 m/year, historical measurements done between 1927 and 2019 reported a recession of 0.76 m/year. Future prediction using the modelling tool SCAPE, showed how, within 20 years, the ridge recession will effect the structure. When modelling future intensification of storm events, it is found that recession rates could have a significant increased, by 40% in certain conditions. The results demonstrate that "Taubanestasjonen" is in serious jeopardy and its future can be compromised in within a few years. Therefore, it is necessary to take immediate actions to preserve the integrity of the structure.