Changes in climate indicators of degradation of UNESCO cultural heritage sites in the European part of Russia

Abstract

Cultural heritage sites are under threat of destruction due to the impact of climate change and related hazards such as rainstorms, floods, droughts. High vulnerability to natural disasters and important historical and socio-cultural value require special attention to World Heritage properties. The goal of the work is to assess the impact of climate on the destruction of building materials of UNESCO cultural heritage sites for four cities in the European part of Russia (Derbent, Kazan, Petrozavodsk and Pskov). The work uses daily data on air temperature and precipitation for the period 1961–2020. Five indices were used to assess the impact of frost (days with air temperatures below 0°C and minus 5°C, freeze-thaw cycles, Wet-frost index and frost decay exposure index) and two indices of extreme air temperatures and precipitation (percentage of days with maximum air temperature higher 90th percentile and number of days with precipitation above 99th percentile). In addition, changes in the indices between two climatic periods, 1961–1990 and 1991–2020, were estimated. The results showed a reduction in the risk of damage to cultural heritage sites by low air temperatures, while the frequency of freeze-thaw cycles increased in the northern regions against the backdrop of rising surface air temperatures. The change in extreme temperatures and precipitation has a positive trend, which increases the associated risks of destruction of materials of cultural heritage sites. Differences in climatic conditions require an individual selection of indicators to assess the impact of climate change on the destruction of building materials and an integrated approach for each cultural heritage site.