Water management strategies in the Ile River basin (Republic of Kazakhstan) have traditionally relied on historical data without fully considering the potential impacts of climate change. This gap can lead to underestimating the changes in temperature, precipitation patterns, and runoff, hindering effective water resource management. This study aimed to analyze how a changing climate is affecting the Ile River basin’s water regime. Specifically, it investigated trends in temperature, precipitation, and runoff within the basin, emphasizing the importance of incorporating these intra-annual variations when planning water management strategies and hydraulic structures. A detailed analysis of the long-term data was conducted, focusing on changes in meteorological indicators. This included average air temperatures and annual precipitation for elevations above and below 1500 m during cold and warm periods. The analysis aimed to identify and quantify trends of increase or decrease. Meteorological stations were strategically chosen to represent both arid and humid areas within the basin, accounting for the region’s significant altitude variations. The investigation revealed several key findings. Rising average annual air temperatures are leading to a larger area experiencing snowmelt and a longer warm period within the runoff formation zone. This directly impacts the water balance of the basin. Additionally, an increase in total annual precipitation, particularly during the cold season within the runoff formation zone, suggests a potential for future water resource growth, assuming that these trends persist. This study highlights the importance of considering intra-annual variations in water regimes when developing water management strategies. The observed changes in temperature and precipitation patterns within the Ile River basin necessitate adjustments to existing plans to ensure sustainable water resource management in a changing climate.

This article provides a comprehensive analysis of long-term changes in the minimum river flow of the southern rivers of Western Kazakhstan (Temir, Oiyil, Zhem) for the period 1940–2022, with an emphasis on summer minimum and winter low flow as key indicators of water and environmental sustainability in conditions of increasing climate variability. The study combines a typology of the climate control mechanisms of minimum flow, analysis of structural homogeneity, and assessment of the internal organization of time series based on ITA and the integral IPTA method, which allow us to reveal the hidden fluctuations and stable phase states of the hydrological regime. The calculation of the climate sensitivity index (CSI_min) showed pronounced seasonal asymmetry: summer runoff is largely controlled by atmospheric precipitation, while winter minimum runoff is determined by temperature regime and soil freezing depth. Parametric and nonparametric tests (Pettitt, ADF, SNHT) revealed significant structural shifts in the 1960s–1990s period, corresponding to large-scale climatic anomalies in the region. Summer series are characterized by phases of prolonged low water levels and negative trends in the mid-20th century, while for the winter period, a steady increase in minimum flow has been established, due to regional warming and an increase in the share of underground recharge. IPTA confirmed the presence of long-term phases with high internal heterogeneity in the summer season and a more stable winter runoff structure. The results demonstrate the high climatic sensitivity of minimum runoff and confirm the need to move from static standards to dynamically adaptable methods of water resource assessment. The proposed approach can serve as a tool for developing adaptation strategies, assessing the risk profile of basins, and improving the sustainability of water management planning in arid regions.

Droughts represent a major threat to water security and agricultural sustainability in the arid regions of Central Asia. The Balkhash–Alakol water management basin is particularly vulnerable due to its complex runoff formation, dependence on surface water resources, and the transboundary nature of the Ile River, the main inflow to Lake Balkhash. This study analyzes hydrometeorological data for 1950–2023 using the Standardized Precipitation Evapotranspiration Index (SPEI), Streamflow Drought Index (SDI), and Surface Water Supply Index (SWSI). Satellite-based indicators, including the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST), were used to derive the Vegetation Condition Index (VCI), Temperature Condition Index (TCI), and Vegetation Health Index (VHI) for 2002–2023. Results indicate a significant increase in drought frequency and duration since the 1990s, with SPEI values reaching −2.6 during extreme events. Satellite observations revealed widespread vegetation degradation, with drought-affected areas (VHI < 30) exceeding 60% of the basin in severe years. Strong correlations between meteorological and hydrological drought indices (r up to 0.9) highlight the importance of cumulative moisture deficits. The results indicate an increase in the region’s aridity and the manifestation of drought in climatic, hydrological, and ecosystem changes. The practical significance of this study lies in the potential to use these results to improve drought monitoring and early warning systems, assess water risks, and develop measures for adapting to climate change and making decisions regarding water resource management in the Balkash–Alakol water management basin.

В статье проанализирована эволюция развития научных публикаций по теме гидрологической засухи. Анализ хронологической динамики и структуры публикаций показал рост научного интереса в данной области и значительное расширение направлений исследований на международном уровне. В качестве методологической основы для подготовки статьи были использованы различные научные публикации, посвящённые проблеме гидрологической засухи, а для библиометрического анализа была выбрана наукометрическая база данных Web of Science. За последние два десятилетия основные направления исследований сосредоточились на совершенствовании индексов засушливости, оценке влияния климатических изменений на засуху, разработке методов моделирования и прогнозирования, применении спутниковых технологий, а также анализе антропогенных воздействий. В условиях Казахстана проблема гидрологической засухи имеет особую актуальность, так как напрямую влияет на доступность и устойчивое использование водных ресурсов. Рост публикационной активности в мировой науке и интеграция новых методов (дистанционное зондирование, климатическое моделирование, искусственный интеллект) открывают возможности для совершенствования систем мониторинга и прогнозирования водных ресурсов на национальном уровне. Включение казахстанских исследований в международное научное пространство способствует не только укреплению научного развития страны, но и формированию стратегий адаптации в условиях изменения климата и роста природных рисков.

This study investigates the spatiotemporal variability, spatial consistency, and non-stationarity of meteorological and hydrological droughts in three major water management basins (WMBs) of northern and central Kazakhstan: Nura–Sarysu, Esil, and Tobyl–Torgai. Long-term instrumental observations from meteorological stations and hydrological gauges were used to calculate the Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), and Streamflow Drought Index (SDI). Structural changes were detected using the Pettitt, Buishand, and CUSUM tests, while spatial consistency was quantitatively assessed as the proportion of active meteorological stations simultaneously experiencing drought conditions. The results showed that major drought episodes represented spatially coherent regional events rather than isolated local anomalies; however, their spatial extent varied substantially among the basins. The highest synchronization of meteorological droughts was observed in the Esil WMB, whereas the Tobyl–Torgai WMB exhibited greater spatial heterogeneity. Statistically significant structural changes were identified in both meteorological and hydrological drought series; however, their timing and frequency differed among indices and basins, indicating pronounced temporal non-stationarity. A higher proportion of structural changes was identified for SPI-3 than for SPEI-3. However, this difference is interpreted as reflecting differences in the statistical behavior of the precipitation index and the climatic water balance index rather than direct evidence of the relative contributions of precipitation and atmospheric evaporative demand. SDI-12 exhibited more persistent and temporally smoothed hydrological drought dynamics compared with the short-term meteorological indices, while the timing of hydrological changes differed among river systems. The results demonstrate that drought development in Northern and Central Kazakhstan is characterized by spatial heterogeneity and temporal non-stationarity, while the joint interpretation of SPI, SPEI, and SDI provides a more comprehensive basis for basin-scale drought monitoring and adaptive water-resource management.