Assessment of Ulaаnbaаtar sustainable development on the basis of soils geochemical analysis

Abstract

Introduction. Assessment of the ecological state of mountainous areas and, especially, large cities, in particular the city of Ulaanbaatar, the study of anthropogenic pressure on sensitive mountain landscapes is very relevant. This is important from the point of view of the contribution of the ecological structural component to the sustainable development of the mountainous area. However, the lack of data on the spatial distribution of the microelement composition of the soil of the urbanized mountainous landscape, especially heavy metals, does not allow a Complex estimationof the ecological state of the territory of the mountainous capital of Mongolia. The purpose of the research: ecological assessment of the soil cover of the metropolis of Ulaanbaatar using geochemical parameters and GIS technologies. Materials and methods of research. Field and physico-chemical methods of studying soils, as well as GIS technologies were used to obtain halo maps of the distribution of anthropogenic pollutants - heavy metals Pb, Cu, Ni, Zn, Hg and oil products. Research results. It was revealed that the key parameter of the state of the soil, the pH indicator, reaches 8-9 units, which means alkalization of the surface soil layer. An active ion-exchange complex has been formed, which leads to the accumulation of technogenic pollutants in the soil. The contents of metals Pb, Cu, Ni, Zn, Hg exceed their standard values based on MPC (MAC). With the use of GIS, halos of their distribution, as well as oil products in the territory of Ulaanbaatar, were obtained. Discussion. Sources of heavy metals are emissions from thermal power plants operating on lignite. Yurts also contribute to severe soil pollution, as they are heated by coal stoves. A large number of personal vehicles and a chaotically located network of gas stations supply metals and petroleum products to the soil. The formation of sparingly soluble fixed forms of metals as a result of alkalization led to their accumulation in the soil. Linear local fields of metal pollution have been identified, which clearly indicate the ecological trouble in the city and the need to take environmental protection measures. Conclusion. The parameters of the geochemical state of techno-genically altered mountain soils in the city of Ulaanbaatar revealed contamination with heavy metals and NPs. Local pollution modules with the accumulation of chemical toxicants have been formed. The halo maps of their distribution are obtained, the formation of a spatially linear type of pollution of the mountain landscape is shown. Offers. The possibility of zoning the territory according to the degree of environmental safety is shown. This should be taken into account in the social and economic aspects of the development of the metropolis, as well as to create a safe living environment for people, to optimize architectural development, to regulate the placement of a network of gas stations, highways and, especially, yurts.