Assessment of moisture availability and dryness during the growing season in the almaty region

The novelty of this study lies in the integrated assessment of moisture availability and dryness during the growing season in the Almaty region over 1990–2024 using SPI-6 and SPEI-6 indices combined with NDVI-based vegetation response, providing new insights into climate-driven agricultural vulnerability in Central Asia. Under recent climate variability, an analysis of moisture availability and aridity and their distributions during the growing season in the Almaty region was conducted based on long-term data (1990–2024) on temperature, precipitation, moisture coefficient, hydrothermal coefficient (HTC), standard precipitation index (SPI-6), standardized precipitation-evapotranspiration index (SPEI-6), and NDVI satellite observations. It was found that the region is characterized by high spatial and temporal variability of climatic parameters. The average long-term temperature deviation during the growing season was 1.2 °C (maximum 1.8 °C in Kegen), the greatest precipitation variability was recorded in Esik and on the Almaty Kamensky Plateau, and the least in arid areas (Aul 4, Bakanas). The humidity coefficient varies from 0.33 (severe aridity) to 2.0 (excessive humidity), with HTC indicating non-arid conditions in the mountains (≥ 0.8) and severe aridity in desert areas (≤ 0.4). The SPI-6 and SPEI-6 indices revealed an increase in the frequency and intensity of droughts, especially in flat areas, while the NDVI confirmed vegetation stress during dry periods. The region's climate variability is manifested in both a trend towards aridification and short-term phases of excessive moisture (2016), with 2021 being the driest year on record. The results confirm the high climatic vulnerability of the Almaty region and the need for adaptation measures in the agricultural sector.