Changing climatic indicators and mapping of soil temperature using Landsat data in the Yangan-Tau UNESCO global geopark

Abstract

Changes in key climate index affect ecosystems and biodiversity. In this regard, the assessment of the climatic conditions is of particular relevance. This study presents the results of an analysis of climate change and digital mapping of soil temperature in the Yangan-Tau UNESCO Global Geopark (Russia). The steady increase in air temperature was revealed, which causes an increase in the sum of active temperatures and the duration of the warm period of the year. Annual total precipitation during 1966-2020 changed the sign of the trend: positive trend (increase in precipitation) in 1966-1990, while in 1991-2020 is negative. The hydrothermal indicators determined the increase in aridity during the warm period. Based on the analysis of changes in the climatic conditions of the geopark, a comparison was made of the temperature regimes of air and soil, and the relationship between these indicators in the snow-free period was revealed (R2 = 0.62). An approach is presented for digital mapping of the temperature regime of the surface layer of soils based on ground-based research data and the results of interpretation of the Landsat thermal bands. A significant relationship between soil temperature and Earth surface temperature for the snow-free period was revealed (R2 = 0.83). Based on the obtained regression model and Landsat 8-9 data for the snow-free period of 2013-2022 the map of the distribution of average temperatures of the surface layer of soil from May to October was produced, which clearly demonstrated the relationship between soil temperature and biomes. Keywords: soil temperature; surface land temperature; remote methods; climate change; Yangan-Tau UNESCO global geopark; Bashkortostan.