Improvement of design solutions for low-pressure irrigation and drainage facilities in a changing climate in the Zarechnaya group of Yakutia

Abstract

The regional temperature increase observed in recent decades has led to a noticeable increase in the amount of atmospheric precipitation, as well as to an increase in the water content of small rivers. As a result of these phenomena, changes in the engineering and geocryological conditions of the foundations of hydraulic structures occurred, cryogenic processes in the water areas of reservoirs became more active, which significantly reduced the stability of irrigation and drainage facilities. On the example of a typical low-pressure hydroelectric complex of the Zarechnaya group of Yakutia, the possibility of improving the design solutions of existing irrigation and drainage facilities based on the substantiation and development of measures to increase water availability in a changing climate is considered. The analysis of the data obtained in the course of the study confirms that due to the warming of the climate observed in recent years, there have been changes that negatively affect the stability of the frozen foundations of irrigation and drainage facilities, in particular, an increase in the layer of seasonal thawing of permafrost soils and an increase in the water content of small rivers exceeding the established initial carrying capacity. structures. In order to increase water availability in a changing climate, additional measures have been justified and introduced to improve the design solutions of the existing hydraulic structure, which consist in increasing the throughput of the structure and improving anti-seepage, heat-insulating and anti-heaving measures.