Optimizing the use of water resources of mountain rivers of the Greater Caucasus (case study on the Gudyalchay river)

Abstract

The aim of the thesis is to study and propose effective solutions to the management of the Greater Caucasus River, in the example of the Gudyalchay river. The Greater Caucasus rivers are mainly spring-fed rivers, which come from the high mountainous areas. High water periods coincide with intense snowmelts observed mostly in early April, while low flows come in late August or early September. Water resources of the target region are mostly used for irrigation and drinking water, which is mostly required late summer months. This pattern requires effectively optimizing the water resources in the river of the Greater Caucasus. In most cases, it is proposed to regulate the flow of the river to solve this problem. However, flow regulation in parallel leads to the loss of very valuable ecosystems. These ecosystem services include mostly cultural and regulating services, such as the provision of spawning grounds for migrating fish, as well as tourism. In this study, methods and techniques are used to determine the years in which the impact of human economic activity on river flow began. These methods are based on comparing the flow of disturbing rivers with the flow of rivers with a natural regime of precipitation in the basin. Based on observations of natural flow, the dependence of river flow on the main flow-generating factors is studied, and the analytical relationship between these factors and the flow is found. Then, due to these dependencies, the natural flow is calculated for the period of anthropogenic factors on the flow and is quantified based on the difference between the flow observed with the natural flow. Using the multiplicity correlation between precipitation and temperature, the change in flow was quantified based on possible precipitation and temperature changes. According to the given formulas, it is possible to determine the impact of climate change on both, non-seasonal and annual flows. New proposals have been made to calculate the total evaporation from the river basins. The average multi-year value of evaporation from river basins was found based on these proposals. The effect of evaporation and solubility on the river flow was determined by hydrographs. The importance of snow waters in the nutrition of Gudyalchay, Damiraparanchay, Gusarchay, Agsuchay, Balakenchay and Goychay rivers was noted. The formula for calculating the natural flow according to water balance methods is given.