Characteristics of the slope and river runoff transformation and its influence on the activation of erosion and fluvial processes – a case study of small river basins in the Southern Urals and the Cis-Urals

The paper presents an analysis of characteristics of changes in the slope runoff and the maximum water discharge during spring floods in small and medium river basins located in the Ural region. It has been shown that the ongoing degradation of natural catchment systems is manifested not only in the form of a reduced number of species in plant communities and their productivity, but also by transformations in the slope runoff and an increase in the maximum values of slope runoff during spring floods in river basins of different categories. This is evidenced by our longterm observations conducted at nature research stations and during long-term research expeditions. The growing human impact is accompanied by a large number of negative economic and ecological processes occurring in river basins and they should be addressed immediately. These processes are manifested in the form of erosion, riverbed deformations, as well as flooding and destruction of various objects, etc

Current trends in the development of channel deformations in small and medium-sized rivers (rivers of the Southern Urals and the Cis-Urals – the case study)

The paper considers the main regularities indicating the activation of channel deformations in small and medium-sized rivers as a result of changes in slope and river runoff depending on the impact of degradation of landscape-na-ture complexes on catchment areas in the Southern Urals and the Cis-Urals as a result of human economic activity. The paper shows that changes in slope and river runoff contribute to the formation of the maximum water flow rate and the destructive force of water flows at the level of overlapping anthropogenic factors and natural historical processes. In accordance with the above, long-term changes in small and medium-sized river channels may occur in a multidirectional way. For example, it has been established that significant changes occurred in the conditions of increasing climate aridity and the growing human impact on landscape-nature complexes in the basins of small rivers in the period from the 1940s–1950s to the 1980s–1990s. They consist i.a. in the transformation of some small rivers of the 1st order into intermittent streams, or changes in the pattern of the hydrographic network

The main characteristics of slope and river runoff transformations under the conditions of degradation of natural complexes on the catchment

The article shows that conducting hydrological calculations in the basins of very small and small rivers and their catchments is associated with significant errors, which is accounted for not only by the drastic limitations of the observational materials, but is also due to significant slope and river runoff transformations depending on the impact of natural complexes degradation (plant communities, soil cover, etc.). In the meantime, it should be noted that the emergence of a number of adverse processes, such as the propagation of erosion and channel processes, floods, environmental and economic damage inflicted on natural and economic systems, etc. is largely associated with the slope and river runoff transformations. This predetermines the necessity of investigating the processes in question. Given the above-mentioned, the article serves to reflect the results of research conducted within the mountain forest area of the Southern Urals and the Cis-Urals by the academic staff of the Department of hydrometeorology and geoecology of the Bashkir state university from 1955 to 2012. The main factors contributing to the increased maximum water discharge during the spring flood are confined to an increase in the modules of runoff coefficients as the scale of anthropogenic load on natural complexes increases, and, consequently, to a decrease in the natural water-regulating capacity of the catchments. The above-mentioned processes have resulted in the increasing maximum values of slope and river runoff and account for the adverse effects observed in the natural, economic and ecological systems

Assessment of Chemical Properties, Heavy Metals, and Metalloid Contamination in Floodplain Soils under the Influence of Copper Mining: A Case Study of Sibay, Southern Urals

The ecotoxicological condition of soils around mining areas is most often unsatisfactory, which affects entire ecosystems and human health. This research sought to analyze the morphological, agrochemical properties, and content of heavy metals (Cd, Cu, Zn) and metalloids (As) of soils located in a floodplain. The study was conducted within the city of Sibay (Republic of Bashkortostan, Russia). The soil samples were collected from the floodplains of the rivers Karagayly and Khudolaz. According to morphological studies, the soil cover was represented by the Lithic Leptosols, Stagnic Phaeozems, and Fluvisols. The results showed that the soils were characterized by high values of organic matter, potassium, and low levels of phosphorus. Soils that were located away from the city in the Karagayly River were not contaminated. However, the floodplain areas pertaining to the urban district and located near the quarries were characterized by severe anthropogenic soil pollution, disrupted integrity of the soil cover, decreased vegetation, and accumulating labile forms of heavy metals and metalloids. The highest degree of pollution was observed in the floodplain soil of the river Khudolaz where all elements exceeded the maximum permissible concentration (MPC) level. Soils in the floodplain of the Karagayly river were marked by an increased degree of contamination of Zn: exceeding MPC by 1.6 times. With the trend toward an arid climate, the ecotoxicological condition of floodplain soils is an important challenge