Problem definition. In order to fully and rationally use water resources (irrigation of arid territories, water supply of the population, etc.), it is necessary to develop the most effective ways of studying river runoff and its components, identifying patterns of its formation and passage, as well as finding ways of its rational use. From this point of view, the patterns identified by the author, as well as the interrelations of river runoff elements and natural factors, acquire important scientific and practical significance and allow us to determine the nature of runoff formation, its intra-annual and long-term distribution across the territory and altitudinal zones. Analysis of recent research. Unlike other natural resources, water resources have the ability to constantly renew themselves due to the moisture cycle in nature. This creates confidence in sufficient water supply for all human needs in the future. Meanwhile, the water resources of the republic are limited. Situated in the middle and lower reaches of two interstate rivers, the Kura and the Araz, it has an influx of river waters from neighboring countries: Turkey, Iran, Georgia, Armenia, and Dagestan. The river flow formed on the territory of the republic is very small. Reservoirs of long-term and seasonal regulation created on rivers to some extent solve the problem of irrigation. However, the issue of providing water to the population of cities, villages and urban-type settlements remains urgent today. Formulation of the purpose of the article. Continuously changing in space and time during the water cycle in nature, all sources of water resources (precipitation, runoff, evaporation) are closely interconnected. Studying the formation of river runoff in any mountainous country is associated with a number of difficulties caused by sharp contrasts in natural conditions. Without taking into account the interaction of these factors and their influence on river runoff, it is unlikely that it is possible to identify the main patterns of change in runoff and its components The main material of the research. During the research, we used field research methods and modern methods. We also used materials from other researchers. Conclusions. As a result, the following landscape-hydrological regions were distinguished in the Nakhchivan natural region. 1. Zangezur-Deralayaz landscape-hydrological region; 2. Shahbuz-Ordubad landscape-hydrological region; 3. Arazboyu landscape-hydrological region. During the analysis of the density of the river network by landscape, we determined that this indicator also affects the socio-economic infrastructure located in hydrological regions.
Ibrahimova et al. (Sun,) studied this question.