The global water crisis, which intensifies each year, underscores the urgent need for accurate assessment and sustainable management of freshwater resources. Lakes, as significant components of surface water systems, are particularly vulnerable to human activities and climate change due to their slow renewal rates. Western Kazakhstan, a region affected by economic development and intensive mining activities, faces acute water scarcity. A reliable water supply is crucial to meeting the requirements of industrial operations and the needs of the region’s population. Understanding the dynamics of lake systems and implementing effective conservation and restoration strategies are essential to addressing this challenge. This study, employing cartographic and remote sensing techniques, identified 323 lakes in Western Kazakhstan, covering a total area of 1944 km². Comparative analysis with historical data from the 1960s and 1970s revealed a 23% decrease in the number of lakes exceeding 1 km². The most significant decline was observed in the Atyrau and Mangystau Regions, where the number of such lakes diminished by a factor of three. These findings highlight the pressing need for an integrated, interdisciplinary approach to water resource management in Western Kazakhstan.

The surface water resources of the West Kazakhstan Region (WKR) face escalating vulnerability due to the synergistic effects of a sharply continental climate, which intensifies climate change impacts, and rapidly increasing anthropogenic water demand. This study aims to quantify and project the future water stress on WKR’s surface waters, assessing the combined influence of climate change and socio-economic development over the critical period of 2030–2050. This study presents a comprehensive quantitative assessment and future projection of water stress on the region’s surface waters, integrating state-of-the-art CMIP6 climate scenarios (SSP2-4.5 and SSP5-8.5) with a novel model of water consumption growth accounting for regional demographic and economic developments. Employing advanced bias-corrected ensemble climate projections alongside physically interpretable water balance models, we estimate changes in river flows and lake volumes through mid-century. A newly developed Water Stress Index (WSI), supplemented by the Falkenmark Index, reveals an alarming increase in water stress, with projections indicating that over 70% of the WKR territory may face severe resource limitations by 2050. The analysis underscores significant spatial heterogeneity driven by climatic variability and socio-economic factors, emphasizing the urgent need for regionally tailored adaptation and water management strategies. These findings provide a robust scientific basis to guide policy decisions aimed at mitigating future water scarcity under evolving climate and development scenarios.

This study investigates the transformation of river runoff and its sensitivity to changes in large-scale atmospheric circulation in the Zhaiyk–Caspian water management basin during the period of 1951–2023. The analysis is based on hydrometeorological observations data, the Vangengeim–Girs classification of macro-circulation patterns, and the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices. Correlation analysis, the Mann–Kendall test, Sen’s slope estimator, and the Pettitt test were applied to identify trends, structural shifts, and the spatial coherence of hydroclimatic changes. The results show that interannual variability in river runoff is characterized by a degree of spatial coherence, with correlation coefficients between annual streamflow records at most gauging stations reaching up to 0.95. It is demonstrated that the most pronounced changes in the hydrological regime occur during the cold season and are expressed in a statistically significant increase in winter runoff, while no significant long-term trend in annual runoff is observed. Structural shifts in winter runoff are predominantly associated with the late 1990s, whereas changes in the temperature regime are detected earlier and exhibit spatial coherence. The findings indicate that the contemporary transformation of river runoff is primarily driven by rising air temperatures and the associated intra-annual redistribution of flow.

Lake bathymetry is of great importance for water resources management and hydrological modeling. Bathymetric mapping of lakes was predominantly conducted with the use of highly-priced methods such as airborne lidars, active imaging sonars, multibeam echosounders. With the advancements in GIS and emergence of remotely sensed data new approaches for bathymetry extraction were developed. However, despite a high motivation to obtain bathymetric information for small lakes from remotely sensed data, there is a lack of reliable methods that can be implemented under various climate conditions and on a wide scale. In this paper several remote-sensing-based methods for bathymetry mapping of small lakes are discussed. The new Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) data was used to extract bathymetric information on three small lakes of Kazakhstan. The assessment of ICESat-2 for lake bathymetry extraction was conducted using field measurements as the validation data.

This study analyzes and evaluates the relationship of surface and groundwater of the Syrdarya River within Kazakhstan. The share of groundwater recharge of the river was calculated by two methods: by genetically partitioning the total runoff hydrograph and by calculating low f low. The difference of groundwater flow into the river between the selected hydrostations is also calculated. A comparison of the obtained results for the quasi-natural and disturbed periods is made. In natural conditions, the infiltration of river runoff into underground horizons prevailed along the length of the Syrdarya River, however, under the influence of anthropogenic activity, the picture changed to the opposite: the discharge of groundwater prevails along the length of the Syrdarya River, including the emergence of filtration waters below the dam of the Shardara HPP, collector-drainage and discharge waters from irrigation f ields of the adjacent territory. Also, apparently, the truncation of spring flood peaks leads to an increase in the groundwater level and an increase in the share of underground river supply. Recommendations for the application of the methods used in the work are given.

This paper discusses assessment of the water sources of Western Kazakhstan. It is one of the territories with the lowest water supply in the country, consisting of Aktobe, Atyrau, West Kazakhstan, and Mangystau regions. The distribution of water resources was assessed by administrative units. When assessing renewable water resources of rivers and streams by administrative units, it is necessary to identify a local runoff, inflow from adjacent administrative units, outflow from the assessed administrative unit, as well as the total resources of administrative units. Currently, small-scale maps, satellite and geoinformational images are used for a more accurate identification of the number of water bodies in the region and the lake percentage in certain areas. The impact of anthropogenic activities significantly distorts natural water reserves, the anthropogenic load on river runoff and lake resources has been assessed. A number of maps were built, namely, specific water supply of the population and territory with total resources; lake percentage; load on total resources; and an indicator of water stress of total resources by administrative units. Thus, surface water resources of Western Kazakhstan are fresh water reserves contained in such water bodies as rivers, lakes and reservoirs, amounting to 14600 million m3.