## 2 Materials and Methods  
Field studies were carried out during trips to the Yamal region (Western Siberia, Russia) between 2019 and 2024. This area belongs to the Arctic zone of the Russian Federation and consists of six natural subzones. The research was conducted in the tundra and forest-tundra regions, which are the most populated parts of the Yamal region. The parent materials are presented by loans and clays with spatial alternations of sands. The climate is Dfc subarctic type with long winters and very short summers according to the Koppen classification [45]. In the case of the cities of Nadym and Novy Urengoy, private cars were used. In the case of remote settlements, which are usually located along river banks, water transport was employed. This significantly affects the degree to which the territory is explored, since it is very difficult and expensive to penetrate deep into watershed territories. Additionally, sandy parent materials often dominate in coastal areas, determining the specifics of the background soils that are transformed during human activity. As a result, research is geographically limited in these areas. In total, about 22 soil sections were described according to the WRB 2022 y. version [4], and about the same descriptions of the area and landscape were provided; key cities and settlements are given in Figure 1. Traditional methods in Russian classical soil science were used, including comparative geographical and comparative morphological methods. Soil diagnostics were carried out according to substantive and morphological features [3; 4; 5]. The field strategy was as follows: a background ecosystem, a recreational area, a residential area, and an industrial area were identified, where at least one soil section was laid. In other cases, we were only able to survey natural and uric soils for various reasons. All the soils and landscapes were provided by [PERSON] from his personal archive. The purpose of this work was to characterize the morphology and genesis of various soils; thus, we did not use a statistical method, because every soil is unique in terms of morphology and profile organization. Unfortunately, we do not have information about the properties of soils prior to urbanization. Previous soil research in the area focused on natural soils, and we began our study of the morphological organization of urban soils in this region. We also do not have access to chemical or physical analytical data about soils prior to urbanization or in the literature. The same applies to the composition and properties of the material being transported; it is only known that it is local. In this regard, the article is mostly descriptive; we added this feature of the study to the description of the methodology. It is not possible to build space-time models based on limited and sometimes single data. This is the task of a separate article in the future. With regard to local authorities, their soil data are very scattered and mainly relate to petroleum products and biological indicators of pollution. Laboratory methods: All the chemical analyses were performed in the soil fine earth (<2 mm) fraction. The pH values were measured using the potentiometric method for the ratio of soil weight to volume--1:2.5 for water and 1:2.5 for a 1 n CaCl solution [46] with a detection limit of 0,1 pH unit. Soil carbon content was determined on a CHN analyzer (EA3028-HT EuroVector, Pravia, PV, Italy) with a detection limit of 0.05 gravimetric % of carbon. Cation exchange capacity (CEC) was measured in bulk soil samples using the Bobko-Askinazi-Aleshin method [47] in BaCl\({}_{2}\) buffer solution (pH = 6.5) via titration, ending with a detection limit of 0.1 CMP+/kg unit. Determination of the heavy metals was carried out via Atomic Absorption Spectrometry (AAS) using a Kvant-2 MT (Cortec, Russia) spectrometer with a detection limit of 0.05 mg/kg.