Logarithmic morphometric–evaporative modeling of hydro-ecological functions of small and medium lakes
نویسندگان
1 Department of Environmental Management and Engineering, Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana, Kazakhstan
2 Department of Environmental Management and Engineering, Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana, Kazakhstan
3 Department of Ecology and Life Safety, Faculty of Engineering, Yessenov University, Aktau, Kazakhstan
4 Faculty of Natural Sciences and Geography, Abai Kazakh National Pedagogical University, Almaty, Kazakhstan
5 Department of Social Sciences Education, Faculty of Education, Bursa Uludağ University, Bursa, Turkiye
6 Department of Science and Innovation, International Educational Corporation Almaty, Kazakhstan
7 The Institute of the Content of Secondary Education, Ibray Altynsarin National Academy of Education the Ministry of Education of the Republic of Kazakhstan, Astana, Kazakhstan
doi
10.22034/gjesm.2026.03.19چکیده
BACKGROUND AND OBJECTIVES: Small and medium-sized lakes are numerically dominant in arid and semi-arid landscapes, yet their contributions to regional water balance and evaporation remain poorly constrained due to limited depth observations. The study objectives were to establish a regionally calibrated morphometric and hydrological framework that connects lake surface area with depth utilizing a logarithmic relationship derived for steppe environments in northern Kazakhstan. The framework enhances current methodologies by allowing for the concurrent estimation of lake depth, water volume, evaporation losses, and hydrological vulnerability in areas with limited data.METHODS: The model was calibrated using morphometric data from 119 lakes in the Karaganda Region and applied to 268 lakes with surface areas of 10 square kilometers or less in the Akmola Region. The study incorporates the distribution of lake sizes, estimates of depth, and models of evaporation, while also presenting a Morphometric Evaporative Vulnerability Index that merges lake area, estimated depth, and regional evaporation intensity.FINDINGS: Lakes that measure between 1 and 10 square kilometers constitute about 80 percent of total lake surface area and approximately 79 to 80 percent of the estimated water volume within the studied lake population. In contrast, lakes that are smaller than 1 square kilometer account for approximately 8 percent of surface area and contribute less than 5 percent of of the total volume. More than 80 percent of lakes have average depths below 2 meters, with about 41 percent concentrated between 1 and 1.5 meters. The analyzed lakes collectively store about 0.97 cubic kilometers of water, whereas the larger lakes contain around 1.24 cubic kilometers. Annual evaporation losses total about 567 million cubic meters, of which medium-sized lakes contribute about 450 million cubic meters, while small and large lakes contribute about 46 and 71 million cubic meters, respectively. CONCLUSION: The results show that shallow and medium-sized lakes are predominant in evaporation fluxes and hydrological sensitivity, attributed to their extensive surface exposure and restricted depth. In contrast, larger lakes mainly serve as long-term reservoirs for water storage. The dominance of shallow lakes, comprising more than 80 percent of the total number, highlights their role as early indicators of hydrological stress. The recommended framework delivers a scalable and data-efficient instrument for evaluating regional lakes, determining their vulnerability rankings, and integrating these findings into water resource management and climate adaptation strategies that utilize geographic information systems.
