Factors influencing surface water changes in the Khar-Us Lake basin, western Mongolia

Authors

  • Tsolmonbayar Galbadrakh School of Arts & Sciences, National University of Mongolia, Ulaanbaatar 210646, Mongolia https://orcid.org/0009-0006-6988-2605
  • Yanjindulam Ganbold School of Arts & Sciences, National University of Mongolia, Ulaanbaatar 210646, Mongolia
  • Li Dingjun School of Arts & Sciences, National University of Mongolia, Ulaanbaatar 210646, Mongolia
  • Altanbold Enkhbold School of Arts & Sciences, National University of Mongolia, Ulaanbaatar 210646, Mongolia https://orcid.org/0000-0003-3810-449X

DOI:

https://doi.org/10.5564/mjgg.v62i46.4140

Keywords:

Climate change, Lake water surface, Trend analysis, NDWI, Climatic factors

Abstract

This study investigates the spatiotemporal variability in the surface areas of Khar-Us, Khar, and Durgun Lakes in western Mongolia between 1992 and 2022 using Landsat imagery and climatic datasets. The Normalized Difference Water Index (NDWI) was employed to extract lake extents, and trend analyses such as the Mann–Kendall test, Sen’s Slope Estimator, and Innovative Trend Analysis Method were used to examine the influence of climate variables - precipitation and air temperature. Results show a statistically significant decline in lake surface area, particularly for Khar-Us Lake, which decreased by approximately 0.43 km² annually. Over the past 30 years, a strong climatic influence has been observed, as indicated by the Mann Kendall (MK) trend (Z = -2 to -6). Air temperature has exhibited a gradual warming MK trend (Z = 0.68), whereas precipitation has shown a declining trend (Z = -0.781). Climatic factors, including reduced precipitation and increasing temperatures, were identified as the dominant drivers. While surface changes in Khar and Durgun Lakes between 2006 and 2010 appear temporally aligned with the operational period of the Durgun Hydropower Plant (HPP), the current study does not include hydrological or operational data to quantitatively confirm causation. Hence, the potential influence of anthropogenic factors is discussed as a hypothesis requiring further research. These findings contribute to understanding the impacts of climatic variability on lake ecosystems in semi-arid regions.

Downloads

Download data is not yet available.
Abstract
90
PDF
48

Author Biography

Tsolmonbayar Galbadrakh, School of Arts & Sciences, National University of Mongolia, Ulaanbaatar 210646, Mongolia

Institute of Geography and Geoecology, Mongolian Academy of Sciences, Ulaanbaatar 15170, Mongolia

References

[1] Dingjun, L., Altanbold, E., Batsuren, D., Tuvshin, G., Yumchmaa, G., Boldbayar, R., & Gansukh, Y. (2023). Changes in the area of lakes in different natural regions of Mongolia and climate effect. Geographical Issues, 23(01), 4-21

[2] Davaa, G., Munkhjargal, B., and Batimaa, P. “Climate change and hydrological regime shifts in the Great Lakes Depression of Western Mongolia,” Hydrology Research, vol. 51, no. 3, pp. 517–530, 2020.

[3] Sumiya, E., Dorjsuren, B., Yan, D., Dorligjav, S., Wang, H., Enkhbold, A., ... & Girma, A. (2020). Changes in water surface area of the lake in the Steppe Region of Mongolia: A case study of Ugii Nuur Lake, Central Mongolia. Water, 12(5), 1470.

[4] Amgalan, M., Matsumoto, T., Ulaanbaatar, T., Nandintsetseg, N., Erdenesukh, S., Sandelger, D., & Altanbold, E. (2020). Estimation of evaporation from Ogii Lake using the energy budget method. Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 76(5), I_301-I_309.

[5] Wang, Y., Liu, J., and Liu, M. “Attribution of water level variation in lakes and reservoirs in arid and semi-arid regions of northern China,” Remote Sensing, vol. 9, no. 6, p. 547, 2017.

[6] Enkhbold, A., Dingjun, L., Ganbold, B., Yadamsuren, G., Tsasanchimeg, B., Dorligjav, S., ... & Boldbayar, R. (2024). Changes in morphometric parameters of lakes in different ecological zones of Mongolia: implications of climate change. Climate Research, 92, 79-95.

[7] Kang, S., Yang, T., Zhang, Q., and Xu, C.-Y. “Response of lake water level to climate variability in arid regions of Central Asia,” Journal of Hydrology, vol. 520, pp. 237–251, 2015.

[8] Liu, D., Liu, M., and Zhang, L. “Monitoring the surface water changes in Mongolia using time-series MODIS data,” Remote Sensing Letters, vol. 10, no. 4, pp. 361–370, 2019.

[9] Enkhbold, A., Vandansambuu, B., Yadamsuren, G., Dorjsuren, B., Dorligjav, S., Gonchigjav, Y., ... & Sumiya, E. (2025). Estimation of morphometric parameters of lakes based on satellite imagery data: Implications of relationships between lakes in the arid region of western Mongolia, Central Asia. Quaestiones Geographicae, 44(1), 21-38.

[10] McFeeters, S. K. “The use of the normalized difference water index (NDWI) in the delineation of open water features,” International Journal of Remote Sensing, vol. 17, no. 7, pp. 1425–1432, 1996.

[11] Wang, J. “Determining the most accurate program for the Mann-Kendall method in detecting climate mutation,” Theoretical and Applied Climatology, vol. 142, no. 3, pp. 847–854, 2020.

[12] Yue, S., and Wang, C. Y. “Applicability of prewhitening to eliminate the influence of serial correlation on the Mann–Kendall test,” Water Resources Research, vol. 38, no. 6, pp. 41–1, 2002.

[13] Freedman, D. A. Statistical Models: Theory and Practice, Cambridge University Press, 2008.

[14] Benesty, J., Chen, J., Huang, Y., and Cohen, I. “Pearson correlation coefficient,” in Noise Reduction in Speech Processing, Springer Topics in Signal Processing, vol. 2, Springer, Berlin, Heidelberg, 2009, pp. 1–4.

[15] Altanbold, E., Byambabayar, G., Amgalan, M., Dingjun, L., Boldbayar, R., Tsolmonbayar, G., & Gansukh, Y. (2024). Implication of climate change on the volume of lakes in the forest-steppe zone, Central Mongolia: Ойт хээрийн бүсийн нууруудын эзэлхүүнд уур амьсгалын өөрчлөлтийн үзүүлэх нөлөө. Geographical Issues, 24(01), 15-32.

[16] Enkhbold, A., Khukhuudei, U., & Doljin, D. (2022). A review of modern trends and historical stages of development of lake research in Mongolia. Proceedings of the Mongolian Academy of Sciences, 25-37.

[17] Malik, A., Kumar, A., Pham, Q. B., et al. “Identification of EDI trend using Mann–Kendall and Şen-innovative trend methods,” Arabian Journal of Geosciences, vol. 13, no. 18, pp. 1–15, 2020.

[18] Güçlü, Y. S. “Improved visualization for trend analysis by comparing with classical Mann–Kendall test and ITA,” Journal of Hydrology, vol. 584, p. 124674, 2020.

Downloads

Published

2025-09-01

How to Cite

Galbadrakh, T., Ganbold, Y., Dingjun, L., & Enkhbold, A. (2025). Factors influencing surface water changes in the Khar-Us Lake basin, western Mongolia. Mongolian Journal of Geography and Geoecology, 62(46), 200–207. https://doi.org/10.5564/mjgg.v62i46.4140