Fornlämningars risk och sårbarhet till följd av vintervägsaltning på det kommunala– och statliga vägnätet i ett förändrat klimat : Litteratur– och fältstudie om korrosion av artefakter, samt identifiering av riskområden genom en GIS–analys i Södermanland

Sammanfattning: Archaeological artefacts excavated today are in a worse preserved state compare to those artefacts found before 1945. Previous research highlighted soil acidification as the main cause. However, not much research has been done to analyse other causalities, such as the spread of road salt during the wintertime and the potential deterioration that salt (sodium chloride) might cause on the physical cultural heritage. Nonetheless, it is proven that salt causes corrosion on infrastructure and on porous stone, masonry, and other composite materials in buildings. The aim of this work is to investigate how road salt move from the road surface (municipal– and state roads) and beyond, what factors might contribute to increased geographical spread and how we can limit the potential risk of damage associated with the spread of road salts to ancient historical sites. The research methods presented in this paper is a mix of field sampling study together with GIS– and literature analysis. The results show that the road salts spread according to an exponential decaying rate, where most of the road salts being spread 5–10 meters beyond the roadside. This means that cultural heritage sites within this buffer–area could be susceptible to salt induced damage to physical structures and deposited artefacts made from metals, rock, brick, and other material. Thereby it is pivotal to highlight the possible actions that can prevent the spread of road salts in a geographical landscape, and its effect on the physical cultural heritage.