Water intake structure for irrigating lands in mountain conditions of the North Caucasus

Purpose: to develop a water intake structure for land reclamation purpose under the conditions of water withdrawal from mountainous natural water sources. Materials and methods. The paper is based on the theoretical analysis of the river hydrological and geological characteristics, which made it possible to calculate the minimum flow required for the stable operation of water intake structure and guaranteed water withdrawal during the growing seasons. The design parameters of the water intake structure were developed using the method of expert assessment with non-parametric statistics by comparing several dependent variables. Having determined the required qualities for a water intake structure, the design of a reclamation facility adapted for the conditions of the mountain and foothill zones of the North Caucasus was developed. Results. To achieve this goal, a static method for analyzing water intake structures was adapted, and statements with a factorial rating scale for expert assessment were developed. Kendall's concordance coefficient was 0.726, the data were consistent, the significance level P was less than 0.05, the differences between the factors were significant. The layer-by-layer latticed type of water intake structure has maximum efficiency. The design of a bottom-type water intake structure has been developed on the basis of the river hydrological regime and the method of water supply to the system. This type of structure demonstrates high efficiency in conditions of difficult terrain and unstable water source regimes during the growing seasons, ensuring stable water intake with minimal impact on the ecosystem. Conclusions. The proposed design of a water intake structure can be adapted to different types of water resources and their fluctuations, which makes it acceptable for mountainous areas with variable water levels in natural water sources. Minimal impact on the ecosystem is ensured by a high degree of water purification without significant changes in river channels.