Digital soil mapping of the boggy plain in the south of the cryolithozone of West Siberia based on multispectral satellite imagery and on-ground soil studies

Soil mapping of the boggy plains of the north of the West Siberian Lowland still remains poorly developed, despite the growing attention to this region from environmentalists due to global warming and its extensive development by the oil and gas producing complex. The territory of the Numto Nature Park was chosen as a testing ground for studying the possibility of soil mapping of boggy plains as it is very typical in terms of the set of presented landscapes inherent in the northern taiga and forest-tundra zones of Western Siberia, including both boreal and frozen bog systems. When compiling the medium-scale soil map, traditional methods of soil survey and geobotanical indication of soils, as well as digital cartography methods based on machine learning were used. Two Landsat-8 multispectral satellite images with a pixel size of 30 meters on the ground from September 8, 2023, were selected as the basis for mapping. The information content of the soil map was increased by including peat mesotrophic soils, as well as soils of wet regressive bogs and khasyrei landscapes (dry lake beds) in the legend. To verify the compiled map the following were performed: 1) its comparison with 30 detailed soil maps of the Kazym basin microkeys; 2) accuracy assessment in the SCP plugin with creation of stratified random points; 3) point repeat ground survey. The accuracy of the map, according to various estimates, ranged from 75.0% to 78.4%. The greatest difficulty is in mapping the soils of small-flat-mound peatlands alternating with thawed complex bogs with dominance of lichens on elevated elements of the bogs. The dominant component of the soil cover in the park is thawed oligotrophic peat soils (share in the soil cover composition is 43.5%). Combinations of oligotrophic peat soils of palsa complexes occupy 11.3%, podzols – 13.3%; complexes of oligotrophic peat (including wet regressive) and mesotrophic peat soils – 8.3%, mesotrophic soils – 7.1%.