Опыт регионального почвенно-геохимического картографирования

Abstract

The developed series of soil-geochemical maps reveals the ecological functions of soils and the soil cover associated with the processes of migration, transformation, and accumulation of chemicals substances in landscapes. The thematic basis for the maps was the electronic version of the soil map of the Russian Federation with a scale of 1 : 2 500 000 and the Unified State Register of Soil Resources of the Russian Federation developed on its basis, as well as regional sources and the database of soil properties of the Perm Territory. Prepared maps represented by two main blocks — basic and applied, each of which, in turn, includes constituent and assessment maps. The article discusses the methodological foundations, the compilation methodology and the content of the presented maps. Baseline maps reveal the most common soil-geochemical patterns of migration and accumulation of substances in soils. The block includes: maps of the thicknesses of organogenic and humus soil horizons, cation exchange capacities, and sorption capacity of soils. These maps make it possible to characterize the sorption properties of surface soil horizons as the most important geochemical barriers for technogenic substances. An analysis of the content of these maps allows us to conclude that the sorption capacity of the most common soils in the region is estimated to be very low and low, due to the low thickness of the humus horizons and low cation exchange capacity of podzolic soils. Podzolized chernozems, soddy-gley and soddy-carbonate soils have an increased sorption ability, but their distribution area is small. The high sorption capacity of soils is associated with a significant thickness of organogenic horizons in hydromorphic soils. The application block is devoted to the analysis of soil properties in relation to heavy metals as a priority group of pollutants for which the soil is a depositing medium. Two maps are included in this block — “Conditions for the migration of heavy metals in soils” and “Sensitivity of soils”. The conditions for the migration of heavy metals highlighted on the map of the same name are represented by 12 options. In the northern and central parts of the region, conditions prevail that combine constant or seasonal recovery conditions and low pH values. In the southern part of the region they are replaced by oxidative weakly acidic. The assessment of the sensitivity of soils to heavy metal pollution is given on the basis of expert assessment. The soils of the region are defined as sensitive and very sensitive, that is, they relatively quickly change their properties to a negative side under the influence of anthropogenic load.