卷 50, 编号 2 (2023)

Long-term variations of water balance components are compared for the deltas of the Pechora and Koluma rivers, flowing in the occurrence area of discontinuous and continuous permafrost rocks. Trends in the variations in the major components of water balance equation (river water flow, precipitation, and losses or increment of runoff in the delta) are considered for the conditions of climate warming (the late XX–early XXI centuries). A distinct increase, most pronounced in 2008–2018, was recorded in the major components of water balance.

Small lakes and reservoirs located in the zone of active technogenesis are subject to the risk of various emergency situations. The present-day computer technologies, including hydrodynamic computation modules, can be used to effectively estimate and forecast their consequences with the aim to minimize the adverse effect. These models require evaluating the coefficients of horizontal diffusion. The theoretical analysis of such processes is very difficult because of their specifics. Studies aimed at evaluating these coefficients in Russia and other countries are very few, even under the assumption of their homogeneity and isotropy. The modern measurement technologies involving the use of pilotless vehicles, make such studies much simpler. The article discusses the significance of such studies, the technology of their performance, and the results obtained for the Verkhne-Zyryansk Reservoir. A field experiment with the use of eight floats yielded an average estimate of the coefficient of horizontal turbulent diffusion equal to 0.012 m2/s. The specific features of the obtained results are discussed.

An analytical study of the problem of water infiltration into a homogeneous unsaturated soil showed that, in the case of periodical water recharge through the soil surface, the character of the flow will tend to uniform with the depth. The stabilization of the flow was found to be due to the effect of two factors: capillary dissipation and nonlinearity. The role of each factor was studied by constructing appropriate exact solutions. An estimate was proposed for the depth at which flow variations become insignificant. This estimate takes into account the joint effect of both these factors. An explicit expression for it contains the hydraulic characteristics of the soil and the main characteristics of the surface recharge regime. The pumping effect was also studied and it was showed that, at some assumptions regarding the soil hydraulic characteristics, it manifests itself in that the time-averaged water content in the top soil layers is less than that at greater depth.

The space and time variations of the concentrations of the most informative hydrochemical characteristics in the Lena R. basin are analyzed for two periods (2010–2014 and 2015–2019) in accordance with the most stringent standards for water bodies used for fishery. The constructed maps of the normal annual unit-area discharge for these components give a space and time characteristic of water quality and reveal the dynamics of hydrochemical runoff variations in the recent years. The effect of climate on surface-water regime in the Lena basin is also considered. The unit-area discharge for the majority of dissolved substances, primarily, the major ions and nutrients, was found to increase at an increase in the total precipitation and to decrease at an increase in the temperature, in which case the effect of precipitation is higher. The effect of temperature on chemical runoff is more noticeable in rivers with predominantly snow feeding, and the effect of precipitation, in rain-fed rivers

This paper presents the results of studying the species composition, diversity, and dynamics of fish communities from the middle reaches of the Belbek River, one of the small rivers of the Crimean Peninsula, which is actively used to eliminate the shortage of water supply in recent years. The river is currently exposed to significant anthropogenic impact. Trends of change in the structure of the fish community with the economic development of the river have been observed and the main forms of negative environmental impact have been identified. A deterioration in the structure of aquatic communities and a sharp decrease in their diversity have been recorded over a short time period. A decrease in the abundance and a deformation of the population structure of native fish species (Crimea shemaya Alburnus mentoides, Crimean barbel Barbus tauricus, and Salgir gudgeon Gobio krymensis) are also observed. The determining influence of hydraulic engineering and hydrotechnical measures on destructive processes in aquatic ecosystems is shown.

The quality of wastewater and the socioeconomic aspects of the life of the population are shown to be interrelated. It is proposed to use municipal wastewater to diagnose the health of the population, to assess the feeding preferences of city dwellers, the use of alcohol, tobacco, medicines, and drugs, to assess the exposure of the population to the effect of hazardous chemicals (PAH, pesticides, preserving agents, plasticizers, etc.), and to timely reveal deceases (including COVID-19). The authors proposed several biomarkers, which are recommended to use to monitor the water-resource system as a component of the urban ecosystem.