Abstract
Soil salinization and inefficient use of water resources in irrigated areas of South Kazakhstan pose a significant threat to the sustainability of agro-industrial systems. This study aims to comprehensively assess soil salinization processes, irrigation system efficiency, and their impact on agricultural crop biomass in the Zhetysai district, located in a water-scarce region. The research covers the period 2015–2024 and integrates geographic information systems (GIS), Sentinel-2 satellite remote sensing data, field observations, and hydromelioration statistical monitoring information. Spatial analysis showed that approximately 45–50% of irrigated lands exhibit signs of salinization, including 15–20% classified as moderately and strongly saline soils. Irrigation water losses during conveyance were significant, with the calculated water delivery coefficient ranging from 0.61 to 0.68, indicating substantial inefficiencies in canal systems. Groundwater levels increased during the observation period, contributing to intensified secondary salinization processes. Areas with high salinity demonstrated Normalized Difference Vegetation Index (NDVI) values reduced by 10–25%, reflecting a decline in vegetation biomass and agricultural productivity. The results provide a deeper understanding of the spatial patterns and driving factors of soil salinization in the Zhetysai district and form a scientific basis for optimizing water resource management, improving drainage system performance, and planning sustainable land reclamation measures. The proposed integrated assessment approach can be applied to other irrigated regions of Kazakhstan to enhance agroecosystem resilience and ecological sustainability.