The use of hydraulic models for carrying out flood simulations is a common practice globally. The current study used HEC-RAS (2D) in order to simulate different flood scenarios on the River Yesil (Ishim). Comparison of different mesh sizes (25, 50 and 75 m) indicated no significant difference in model performance. However, a significant difference was observed in simulation time. In addition, the inclusion of breaklines showed that there was a slight improvement in model performance and a shortening of the simulation time. Sensitivity analysis and the consequent manual calibration of sensitive parameters resulted in a slight improvement (an increase in the model accuracy from 58.4% for uncalibrated to 59.7% for calibrated). Following the simulations inundation maps for 10-, 20- and 100-year flood events were obtained. Hazard classification of the flood extents generated indicated that the settlements of Zhibek Zholy and Arnasay were flooded in all the simulated events. Volgodonovka village experienced flooding when a 100-year flood event was simulated. On the other hand, settlement No. 42 did not experience any flooding in any of the scenarios. The model results also demonstrate that the Counter-Regulator was not overtopped in the event of the 100-year hydrograph.

Flooding events have been negatively affecting the Republic of Kazakhstan, with higher occurrence in flat parts of the country during spring snowmelt in snow-fed rivers. The current project aims to assess the flood hazard reduction capacity of Alva irrigation system, which is located in the interfluve area of Yesil and Nura Rivers. The assessment is performed by simulating spring floods using HEC-RAS 2D and controlling the gates of the existing system. A digital elevation model of the study domain was generated by integration of Sentinel-1 radar images with the data obtained from bathymetrical survey and aerial photography. Comparison of the simulated inundation area with a remote sensing image of spring flood in April 2019 indicated that the main reason for differences was due to local snowmelt in the study domain. Exclusion of areas flooded by local snowmelt, which were identified using the updated DEM, from comparison increased the model similarity to 70%. Further simulations of different exceedance probability hydrographs enabled classification of the study area according to maximum flood depth and flood duration. Theoretical changes on the dam crest as well as additional gates were proposed to improve the system capacity by flooding agriculturally important areas, which were not flooded during the simulation of the current system. The developed model could be used by local authorities for further development of flood mitigation measures and assessment of different development plans of the irrigation system.

The article presents the results of the functional zoning of the delta of transboundary river Syr Darya, which is located in an ecological disaster zone and is the only watercourse in modern conditions that supplies the remained part of Aral Sea. Under the conditions of global climate change, the territories of river deltas in arid regions are subject to active degradation processes, which are associated both with decrease of their water content and increase of anthropogenic impact. To determine the current condition of Syr Darya river delta landscapes, a component-by-component analysis of its main components was carried out. Based on the assessment of use of delta natural resource potential, the degradation processes associated with the types and intensity of anthropogenic impact in the conditions of arid climate were identified. The conducted studies formed the basis for the functional zoning of the territory of Syr Darya river delta, which is a spatial planning of sustainable land use and landscapes preservation. The developed scheme of functional zoning of Syr Darya River delta allowed to propose a number of measures with allocation of landscapes recommended for conservation, restoration, or sustainable use by the certain type of land use with the minimization of degradation processes.

The article delves into the development of a comprehensive concept for the sustainable development of regions characterized by intensive environmental management. This concept is rooted in the interplay of several key factors, including the environmental component, social attractiveness, and infrastructural accessibility. By meticulously analyzing these factors and juxtaposing them with the geographical distribution of recreational facilities, the authors propose the innovative concept of a recreational and functional zone. This concept aims to harmonize environmental, economic, and social considerations to foster sustainable development. In this study, particular attention is given to three districts within the steppe zone of the Aktobe region, which are notable for their high levels of economic development and intensive environmental management practices. The analysis encompasses a thorough examination of the ecological, economic, and sociological dimensions of these areas. The authors explore the intricate dynamics between these components to understand the challenges and opportunities they present for sustainable regional development. Building on this analysis, the article offers specific recommendations and strategies designed to optimize environmental management practices. These recommendations are not only aimed at mitigating potential environmental impacts but also at enhancing the development of recreational areas as a pivotal element of the region's sustainable development strategy. The authors argue that such an approach is crucial for ensuring the long-term viability and resilience of the region, balancing economic growth with the preservation of its natural and social environments.

This dataset provides high-resolution bathymetric data for Yesik Lake, in southeast Kazakhstan's Tien Shan Mountain range. A bathymetric survey was undertaken from September 9 to 12, 2024, using a Lowrance ELITE Ti 9 multibeam sonar placed on a small vessel.

The article provides an overview of anthropogenic factors negatively affecting the geosystems of the Ilek River basin. The accumulation of chemical elements and their introduction into the environment result from human industrial and agricultural activities. The article examines natural and anthropogenic causes that adversely impact the qualitative composition of surface waters in the Ilek River basin. It also considers the hydrological regime of the Ilek River and its major tributaries based on field observations conducted in 2024. The study identifies natural and anthropogenic factors that have been influencing the geosystems of the Ilek River basin for decades. Results of chemical analyses of surface water samples from key sites demonstrate a clear correlation with elements of the technosphere. It has been established that first- and second-order tributaries of the Ilek River, located in the northeastern part of the basin, are polluted with heavy metals due to mining and geological exploration activities. The Water Pollution Index (WPI) was calculated for the Ilek River and its major tributaries. The findings indicate that while the water bodies of Aktobe oblast, which remain underresearched, generally meet surface water quality standards, the surface waters in the middle reaches of the Ilek River are classified as highly polluted. This highlights the necessity for more comprehensive investigations to prevent further deterioration and to develop measures for reducing pollution levels.