Vol. 59 No. 3 (267) (2025)

This study examines the hydrochemistry of mineral and freshwaters circulating in the crater of the Aragats volcano and on its Еastern and Сouthern slopes, as well as to clarifying several related issues. On the Еastern slopes, in connection with the composition of the mineral waters, a natural acid drainage phenomenon has been observed, which propagates downstream along the main tributary and gradually diminishes within the territory of the Tsaghkashen Village. In this area, noticeable differences are also observed in the compositions of waters discharging from outlets located in proximity to one another, which may be explained by the substantial difference in the depths of formation of the mineral and freshwater bodies, as well as by the isolation of their respective pathways to the Earth's surface. The most widespread and dominant water types were distinguished for the investigated sites, and their chemical formulas were determined according to Kurlov's classification.

Using the example of two coastal landforms of the same origin, the impact of modern climate change on their transformation and preservation is considered. The materials from the author’s field research on the Baltic and Caspian Seas were used. On the Curonian Spit, the increased frequency of severe storm surges against the background of rising water levels in the Baltic Sea has increased coastal erosion, especially in its basal part, and threatens to break through the spit into the Bay of the same name. This will lead to the dismemberment of the Curonian Spit with the formation of separate islands. Due to the lowering of the Caspian Sea level, coastal abrasion is excluded on the Gorgan Spit. The body of the spit will expand from the seaward side due to the drainage of part of the underwater coastal slope. The bay of the same name has turned into a saline and brackish swamp. Measures have been proposed to save the Curonian Spit and the Gulf of Gorgan.

Contemporary climate change has precipitated the desiccation of the Aral Sea (Lake) as well as Lakes Chad and Urmia. The first two lakes repeatedly sharply lost their water volume during severe droughts for quite a long time, and during wet periods they recovered again.  Periods of severe droughts and humidification of their basins have been identified. Their current desiccation began in the 1960s and is developing according to a similar scenario. Lake Urmia lost its prehistoric water volume due to the tectonic subsidence of its basin at the end of the Late Pleistocene. In more recent times, fluctuations in its level have been mainly associated with changes in climatic conditions. The current desiccation of all three lakes coincided with a new dry climate cycle, which was superimposed by anthropogenic impact, that have culminated in catastrophic consequences. The lakes can be saved only by completely abandoning the use of river runoff for agricultural purposes. The lakes will gradually recover during the wet climate cycle, which may replace the current dry phase.

This article examines the results of testing a photohydrometric method by large-scale particle-image velocimetry (LSPIV) for determining water discharge over a wide range of flow velocity variations on mountain rivers in the Kuban Basin. The aim of the study is to evaluate the applicability of the proposed technology as an accessible, non-intrusive, and labor-efficient tool for continuous hydrological monitoring of mountain river discharge. During the testing of this method, water discharge was measured using both a current meter and LSPIV. The authors developed an algorithm for assessing the quality of measurement, based on a comparative statistical and graphical analysis of surface flow velocity fields. Additionally, a study of empirical distributions of flow velocities by flow depth is conducted, and their generalized numerical estimates are provided. Conclusions are drawn regarding the specific application of the LSPIV, and recommendations are provided for determining water discharge on mountain rivers using this method.

The study, evaluation, and tourism-oriented utilization of the diverse characteristics of a country's territory, including its underlying natural-resource conditions, play a critical role in national economic development. In this context, the Republic of Armenia is no exception. Despite its relatively small geographical extent, Armenia exhibits remarkable physical and geographical diversity, with pronounced local variations, distinctive features in its natural territorial complexes, and notable aesthetic qualities and tourism appeal. For both international visitors and Armenian citizens, major attractions include not only the country's unique and centuries-old achievements in material and spiritual culture, but also the characteristic elements of its physical-geographical environment. These features are shaped primarily by the variety of Armenia's mountainous landscape and the morphology of its relief. Furthermore, in an era when tourism has become a key economic sector in many countries and contributes significantly to economic diversification, the purposeful and efficient utilization of all components of a country's tourism potential has become increasingly essential.

Design and construction of modern hydraulic structures, which include a hydroelectric power station, dam, shipping lock, earth dam, reservoir, etc., require detailed forecasting of their impact on adjacent territories. Assessment issues are usually considered in accordance with regulatory requirements and involve studying the reservoir's impact on the development of various processes in the coastal zone. For the forecast to be objective, it makes sense to perform it in two stages: the first in the form of a "background" consolidated forecast and the second, in the form of a detailed forecast – after the facility is put into operation in 5 years. This approach will allow taking into account all trends in the development of banks and coastal processes and, if necessary, developing proposals for coastal protection.

At all times, both quantitative and qualitative indicators of human potential or demographic situation have had an essential role in solving various state strategic and tactical problems. Along with other factors, the demographic situation has conditioned the socio-economic growth and development of countries, strengthe-ning of defense capabilities and increase in military potential. To achieve a favorable demographic situation, countries have implemented and continue to implement special demographic policies. In this sense, the Republic of Armenia is no exception, where various processes have influenced the formation of the demographic situation during the Post-Soviet period. Identifying the existing problems of the current demographic situation and pointing out relevant solutions are considered one of the priority directions for the prospective development and socio-economic growth of the Republic of Armenia. In this context, the formation of a favorable demographic situation and effective management is one of the important guarantees for creating a stable security system.