Использование вегетационных и водных индексов для оценки состояния постпирогенных верховых болот Западной Сибири

Abstract

The article presents an analysis of the using vegetation and water indices possibilities to assess the pyrogenic load and post-pyrogenic vegetation restoration in raised bogs. The object of the study is burned out in 2016 site within the drained part of the Great Vasyugan mire. The research based on the vegetation field description data carried out in 2023 and Landsat 8 satellite data. Vegetation (NDVI, VARI, NBR) and water (NDWI WRI) indices for field research plots were calculated, and a statistical analysis of their interrelationships with the degree of pyrogenic load and characteristics of vegetation cover was performed using the principal component method. The effect of the wildfire was manifested in the partial or complete burning of the surface, trees, dwarf shrubs and mosses. Seven years after the fire, there was an almost complete restoration of dwarf shrubs, the appearance of pine and birch undergrowth, intensive overgrowth of burnt surfaces by Polytrichum strictum, and the restoration of sphagnum mosses began. The study showed that the values of all the considered indices, with the exception of NDVI, are lower at post-pyrogenic points compared to unburned ones. Of all the indices considered, NDWI showed the maximum dependence on the proportion of surface burnout and projective coating with sphagnum mosses. Water indices turned out to be more suitable in comparison with vegetation indices for assessing pyrogenic load and trends of post-pyrogenic restoration in conditions of raised bog. The results obtained will be used to create training inputs for decoding satellite data and to conduct a spatial and temporal assessment of the restoration of post-pyrogenic sites.